Suchergebnisse

Relevance of research topic. Recent decades have seen a growing concern for the prospects of today's youth. Major problems of young people are related to pervasive destructive and inappropriate behaviour: delinquency, aggression, bullying, drug abuse etc. (Holt, Jones, 2008; Strachan, Côté, Deakin, 2011). These problems are the result of changing social factors: both parents work full-time, single-parent families, unattended children at home (Strachan et al., 2011). Successful personality development depends on a number of external factors: family, school, positive role models, purposefully and deliberately chosen way of self-realization and leisure time activities. The role of a family for the child's positive personality development is in particular highlighted (Vierimaa et al., 2012). Close and solid relationships between children and parents ensure the consistent feeling of security and confidence (Carr, 2014). Affectionate relations between parents and children influence the formation of close links with other people (Holt, Knight, 2014; Steinberg, 2014). The importance of attachment becomes apparent in adolescence – the period of psychological and social transition from childhood to adulthood (Nawaz, 2011). Early parent–child relationship plays a vital role in this period. Attachment and relationship with parents change in the period of adolescence, young people becoming more independent from their parents. In this period the parent–child attachment weakens as young people are faced with new challenges; they seek independence and self-sufficiency, develop their self-identity. Researchers have noted that secure attachment to family gives adolescents a more secure emotional basis which they can always rely on. Gained self-confidence and affectionate relations help adolescents in developing and maintaining relationships with peers (Nawaz, Gilani, 2011). As adolescents spend most of the time without parents, their personality development is strongly influenced not only by parents, but also by peers (Arnon et al., 2008). Therefore, it is important for adolescents to establish or strengthen the existing relationships with friends (Nawaz, 2011). The time spent with peers enables them to develop and maintain social relationships outside the family, to be independent from their parents, to build their future adult identity, express their needs and develop their culture in a group of peers (Arnon et al., 2008). Communication and time spent with peers is not just having fun in one's leisure time but also an important part of socialization process (Arnon et al., 2008). Meaningful leisure activities have a positive impact on adolescents' development: prevent risky behaviour with negative consequences for the future; ensure better academic achievements; involve into community activities and help to pursue a career in adulthood (Fredricks, Eccles, 2010). Meaningful leisure activities include participation in sporting activities, which, according to scientific research, is one of the most popular after-school activities among adolescents (Šukys, 2008; Tomik et al., 2012). Parental mission is to guide the child into activities that, through continuous participation, would build the child's self-confidence and ability to solve problems, teach aim setting and instil values (Warner et al., 2015). Deliberate practice and its advantages have been widely researched (Strachan et al., 2011; Vierimaa et al., 2012). Participation in sports is one of social activities that has a positive effect on a child's development. This attractive activity with respectable image can lead to positive social changes. Participation in sporting activities gives children the opportunity to enjoy high-quality leisure time; children become more disciplined and active in many different spheres (Rottensteiner et al., 2013). Although organized youth sports provide meaningful activities to millions of children, sociological studies suggest that the number of children engaged in sporting activities is constantly decreasing, and children's negative attitude towards sports, alienation and passiveness is becoming a serious problem (Smoll et al., 2011). Most of researchers acknowledge that parents have the greatest influence in sporting activities of their children (Lavoi, Stellino, 2008; Dorsch et al., 2009; Sapieja et al., 2011; Nunomura, Oliveira, 2013; Holt, Knight, 2014; Knight, Holt 2014; Dorsch, Smith, 2016), that participation in youth sport is the process where parents play the most important role (Sanchez-Miguel et al., 2013). Initially children enjoy sports for small achievements; later on sport becomes a motivating factor, an interesting and meaningful activity that eventually becomes a lifestyle (Wells et al., 2005; Perrotta, Pannelli, 2014; Prichard, Deutsch, 2015; McMillan et al., 2016) passed on to children and grandchildren, i.e. to the next generations. In order to involve children into sporting activities from the early age and to achieve progress in fully disclosing their talents it is necessary to create a favourable environment in the early years of the child's personality development and parents play a very important role in this process (Sánchez-Miguel et al., 2013; Legg et al., 2015; Dorsch et al., 2015; Dorsch, Smith, 2016). The child's success in sports can be regarded as the parents' merit too (Bailey et al., 2013). Parents can shape the child's behaviour and give the right direction (Lavoi, Stellino, 2008; Arthur-Banning et al., 2009; Smoll et al., 2011). Parents are involved in disclosing and recognizing the child's talent (Côté, Vierimaa, 2014), experienced joy from participation in sporting activities (McCarthy, Jones, 2007), understanding the athletic competence (Lee et al., 2008), competition anxiety and stress management experience (Gould et al. 2012), and development of psychological skills (MacNamara et al., 2010). Family relations is the context where answers to questions how and why participation in sporting activities changes the child's thinking and behaviour. Such issues as the role of parents in this process and how they cope with this role, how sporting activities modify not only children's but also parents' personality orientations, behaviour and communication in the family. Research problem. The analysis of Lithuanian and foreign studies in the context of research topic revealed the following problem aspects: only very few athlete children can remain in sports without emotional and financial support from their family (O'Connor, 2011); not all parents are interested in sports and not all parents understand the importance of education through sports (O'Rourke et al., 2014); little is known about the influence of children's participation in sports on parents, their motivation and experience (Wiersma, Fifer, 2008) little is known about the relationship between children's participation in sport and their communication in the family and with peers. Therefore, there is a need to find out how parental involvement in youth sport could be strengthened and supported by recognizing the prospects of children and respecting parental experiences. Research object – educational interaction between parents and adolescents in sports. Research goal – reveal the educational interaction between parents and adolescents in sports. Research objectives: 1. Theoretically ground the educational interaction between parents and adolescents in sports. 2. Disclose the links between participation in sporting activities and attachment to parents and peers among athlete and non-athlete adolescents. 3. Disclose parental experiences related to the involvement into children's sporting activities. 4. Disclose adolescents' experiences related participation in sporting activities and relationship with parents. Expected outcomes of research (hypotheses): 1. A hypothesis that the relationship of athletic children with parents is more affectionate compared to that of non-athletic peers is proposed. 2. A hypothesis that adolescents with longer athletic experience are more attached to parents compared to adolescents with less athletic experience is proposed. Scientific novelty and practical significance of the dissertation The findings of scientific studies done in Lithuania and abroad on family involvement into adolescents' activities are significant in terms of importance of attachment to parents in the period of adolescence. However, integrated research into children's attachment to parents and peers in the context of sport is scarce, and no studies analysing parent–child experiences related to sport and revealing the educational interaction were done in Lithuania. Thus there is insufficient scientific information in this area. Therefore the scientific novelty of the dissertation is grounded on three levels: theoretical, empirical and practical. On the theoretical level this dissertation presents and substantiates the expanded concepts and interpretations of attachment to parents, attachment to peers and educational interaction between parents and children. Until now the constructs representing attachment to parents, attachment to peers, adolescents' participation in sporting activities were analysed in scientific studies as separate issues. In this dissertation these constructs are united into an integral and continuous process of educational interaction between parents and children. A modern theoretical model of educational interaction between parents and children developed and theoretically grounded in this dissertation is significant for its scientific novelty. On the empirical level a quantitative survey of adolescents was conducted in this dissertation in order to analyse the importance of attachment and communication within the family in the period of adolescence. The experiences of parents stemming from the involvement in their children's sporting activities and the experiences of adolescents related to the participation in sporting activities and relations with parents were disclosed in the qualitative survey. Both surveys were combined by a mixed method. These complementing surveys enabled to get a deeper and clearer understanding of parent–adolescent relations and attachment to family in the background of sporting activities. It is not only new approach in the context of Lithuanian research but also expands the available results of empirical research from foreign countries. This approach was used not only with the aim to find out how different variables related to sporting activities (attachment to family, attachment to peers, coaches' input) acting together may add to the expression of positive educational interaction between parents and children in sporting activities. Another new thing is that for the first time in research literature adolescents' attachment to parents is operationalized by two variables (attachment to parents and attachment to peers) reflecting their participation in sporting activities in order to find out, which variable is more important in the period of adolescence. On the practical level the results and conclusions of this dissertation may first of all help managers of sport clubs, organizations, school staff and educators to better understand how parents – by creating positive and supporting relations in sporting activities of their teenage children – may add to the achievement of the goals and objectives and in this way educate democratically minded youth ready to actively engage in social and public life. Secondly, this dissertation is relevant and has a practical value for the promotion of positive development of adolescents and responsible parenting. It opens a new view for professionals (coaches, sport educators, sport psychologists) working with athletes and their parents to the variety of experiences and through the knowledge gained increase the wellness of athletes and their parents. Thus, the clearer aspects of family attachment and experiences of athlete adolescents in their relations with parents may help to improve the skills not only of athlete adolescents but also of their parents and coaches. It should be noted that the findings of this dissertation were implemented in practice – a new intervention programme facilitating the parental involvement in children's sporting activities has been developed. More information about this educational programme is available at www.lisinskiene.com. CONCLUSIONS 1. Scientific literature analysis revealed that parent–child educational interaction in sport is a bi-directional system. Parents influence children: they learn to be emphatic, self-disciplined, self-respected, they build communication skills, and plan their daily routine. Children influence parents because involvement in the child's sport naturally changes parents and modifies their lives: parental daily routine alters, their cognition, knowledge and emotions change, their circle of contacts increases, interpersonal relations with the child, in the family, with other participants in sports also change. Marital relations of parents also alter through the child's participation in sport, some parents start playing sports. Parent–child educational interaction in sport depends on financial and psychological support from parents, the child's physical and emotional security, the coach's positive education strategy, competence and authority. Educational interaction in sport is possible by more active attraction of parents into children's sport; not making pressure on athletic children; motivating them to play sports through psychologically supporting environment; providing continuous training possibilities for coaches. 2. The investigation into the relationship between the adolescents' sporting activities and attachment to family and peers revealed that athlete adolescents' relations with parents are more intensively expressed in all scales: communication, trust and alienation compared to non-athlete adolescents. No relationship was found between adolescents' participation in sport and attachment to peers. 3. Interviews with parents revealed the importance of the coach's role for strengthening parent–child interaction in sport. Parent–child educational interaction in sport depends on the coaching strategy selected by the coach and the degree and form of parental involvement in children's sport. Parents of athlete adolescents acknowledge the benefit of positive coaching and education strategy selected by the coach. This understanding confirms the importance of positive tri-dimensional interaction among parents, children and coaches. However, a phenomenon that has a negative effect on this interaction: parents find it difficult to admit the children's growing attachment to coach. The contraposition to close relations between the child and the coach demonstrated by parents may encourage the alienation between parents and children in sport. 4. Interviews with athlete adolescents revealed that parental involvement into children's sport is more important in the early period of sporting life and becomes less appreciable or unwelcome when children gain sporting experience. In the background of parent–child interrelations in sporting activities adolescents alienation from parents is more common than communication and trust. Alienation of older adolescents from parents in sports has several causes: growing children seek to be independent from their families in sports, some parents behave inappropriately in youth sport and embarrass their children. Interviews with athlete adolescents revealed that some parents demonstrate substandard behaviour in relation to their children, have no loyalty towards other participants of the sporting activity. However, financial support remains and important factor of parental support in all levels of sporting experience. The degree and form of parental involvement into children's sport influences the effectiveness of parent–child educational interaction. The degree and form of involvement chosen by the parents are not always appropriate and encouraging, and not always acceptable to adolescents.

Relevance of research topic. Recent decades have seen a growing concern for the prospects of today's youth. Major problems of young people are related to pervasive destructive and inappropriate behaviour: delinquency, aggression, bullying, drug abuse etc. (Holt, Jones, 2008; Strachan, Côté, Deakin, 2011). These problems are the result of changing social factors: both parents work full-time, single-parent families, unattended children at home (Strachan et al., 2011). Successful personality development depends on a number of external factors: family, school, positive role models, purposefully and deliberately chosen way of self-realization and leisure time activities. The role of a family for the child's positive personality development is in particular highlighted (Vierimaa et al., 2012). Close and solid relationships between children and parents ensure the consistent feeling of security and confidence (Carr, 2014). Affectionate relations between parents and children influence the formation of close links with other people (Holt, Knight, 2014; Steinberg, 2014). The importance of attachment becomes apparent in adolescence – the period of psychological and social transition from childhood to adulthood (Nawaz, 2011). Early parent–child relationship plays a vital role in this period. Attachment and relationship with parents change in the period of adolescence, young people becoming more independent from their parents. In this period the parent–child attachment weakens as young people are faced with new challenges; they seek independence and self-sufficiency, develop their self-identity. Researchers have noted that secure attachment to family gives adolescents a more secure emotional basis which they can always rely on. Gained self-confidence and affectionate relations help adolescents in developing and maintaining relationships with peers (Nawaz, Gilani, 2011). As adolescents spend most of the time without parents, their personality development is strongly influenced not only by parents, but also by peers (Arnon et al., 2008). Therefore, it is important for adolescents to establish or strengthen the existing relationships with friends (Nawaz, 2011). The time spent with peers enables them to develop and maintain social relationships outside the family, to be independent from their parents, to build their future adult identity, express their needs and develop their culture in a group of peers (Arnon et al., 2008). Communication and time spent with peers is not just having fun in one's leisure time but also an important part of socialization process (Arnon et al., 2008). Meaningful leisure activities have a positive impact on adolescents' development: prevent risky behaviour with negative consequences for the future; ensure better academic achievements; involve into community activities and help to pursue a career in adulthood (Fredricks, Eccles, 2010). Meaningful leisure activities include participation in sporting activities, which, according to scientific research, is one of the most popular after-school activities among adolescents (Šukys, 2008; Tomik et al., 2012). Parental mission is to guide the child into activities that, through continuous participation, would build the child's self-confidence and ability to solve problems, teach aim setting and instil values (Warner et al., 2015). Deliberate practice and its advantages have been widely researched (Strachan et al., 2011; Vierimaa et al., 2012). Participation in sports is one of social activities that has a positive effect on a child's development. This attractive activity with respectable image can lead to positive social changes. Participation in sporting activities gives children the opportunity to enjoy high-quality leisure time; children become more disciplined and active in many different spheres (Rottensteiner et al., 2013). Although organized youth sports provide meaningful activities to millions of children, sociological studies suggest that the number of children engaged in sporting activities is constantly decreasing, and children's negative attitude towards sports, alienation and passiveness is becoming a serious problem (Smoll et al., 2011). Most of researchers acknowledge that parents have the greatest influence in sporting activities of their children (Lavoi, Stellino, 2008; Dorsch et al., 2009; Sapieja et al., 2011; Nunomura, Oliveira, 2013; Holt, Knight, 2014; Knight, Holt 2014; Dorsch, Smith, 2016), that participation in youth sport is the process where parents play the most important role (Sanchez-Miguel et al., 2013). Initially children enjoy sports for small achievements; later on sport becomes a motivating factor, an interesting and meaningful activity that eventually becomes a lifestyle (Wells et al., 2005; Perrotta, Pannelli, 2014; Prichard, Deutsch, 2015; McMillan et al., 2016) passed on to children and grandchildren, i.e. to the next generations. In order to involve children into sporting activities from the early age and to achieve progress in fully disclosing their talents it is necessary to create a favourable environment in the early years of the child's personality development and parents play a very important role in this process (Sánchez-Miguel et al., 2013; Legg et al., 2015; Dorsch et al., 2015; Dorsch, Smith, 2016). The child's success in sports can be regarded as the parents' merit too (Bailey et al., 2013). Parents can shape the child's behaviour and give the right direction (Lavoi, Stellino, 2008; Arthur-Banning et al., 2009; Smoll et al., 2011). Parents are involved in disclosing and recognizing the child's talent (Côté, Vierimaa, 2014), experienced joy from participation in sporting activities (McCarthy, Jones, 2007), understanding the athletic competence (Lee et al., 2008), competition anxiety and stress management experience (Gould et al. 2012), and development of psychological skills (MacNamara et al., 2010). Family relations is the context where answers to questions how and why participation in sporting activities changes the child's thinking and behaviour. Such issues as the role of parents in this process and how they cope with this role, how sporting activities modify not only children's but also parents' personality orientations, behaviour and communication in the family. Research problem. The analysis of Lithuanian and foreign studies in the context of research topic revealed the following problem aspects: only very few athlete children can remain in sports without emotional and financial support from their family (O'Connor, 2011); not all parents are interested in sports and not all parents understand the importance of education through sports (O'Rourke et al., 2014); little is known about the influence of children's participation in sports on parents, their motivation and experience (Wiersma, Fifer, 2008) little is known about the relationship between children's participation in sport and their communication in the family and with peers. Therefore, there is a need to find out how parental involvement in youth sport could be strengthened and supported by recognizing the prospects of children and respecting parental experiences. Research object – educational interaction between parents and adolescents in sports. Research goal – reveal the educational interaction between parents and adolescents in sports. Research objectives: 1. Theoretically ground the educational interaction between parents and adolescents in sports. 2. Disclose the links between participation in sporting activities and attachment to parents and peers among athlete and non-athlete adolescents. 3. Disclose parental experiences related to the involvement into children's sporting activities. 4. Disclose adolescents' experiences related participation in sporting activities and relationship with parents. Expected outcomes of research (hypotheses): 1. A hypothesis that the relationship of athletic children with parents is more affectionate compared to that of non-athletic peers is proposed. 2. A hypothesis that adolescents with longer athletic experience are more attached to parents compared to adolescents with less athletic experience is proposed. Scientific novelty and practical significance of the dissertation The findings of scientific studies done in Lithuania and abroad on family involvement into adolescents' activities are significant in terms of importance of attachment to parents in the period of adolescence. However, integrated research into children's attachment to parents and peers in the context of sport is scarce, and no studies analysing parent–child experiences related to sport and revealing the educational interaction were done in Lithuania. Thus there is insufficient scientific information in this area. Therefore the scientific novelty of the dissertation is grounded on three levels: theoretical, empirical and practical. On the theoretical level this dissertation presents and substantiates the expanded concepts and interpretations of attachment to parents, attachment to peers and educational interaction between parents and children. Until now the constructs representing attachment to parents, attachment to peers, adolescents' participation in sporting activities were analysed in scientific studies as separate issues. In this dissertation these constructs are united into an integral and continuous process of educational interaction between parents and children. A modern theoretical model of educational interaction between parents and children developed and theoretically grounded in this dissertation is significant for its scientific novelty. On the empirical level a quantitative survey of adolescents was conducted in this dissertation in order to analyse the importance of attachment and communication within the family in the period of adolescence. The experiences of parents stemming from the involvement in their children's sporting activities and the experiences of adolescents related to the participation in sporting activities and relations with parents were disclosed in the qualitative survey. Both surveys were combined by a mixed method. These complementing surveys enabled to get a deeper and clearer understanding of parent–adolescent relations and attachment to family in the background of sporting activities. It is not only new approach in the context of Lithuanian research but also expands the available results of empirical research from foreign countries. This approach was used not only with the aim to find out how different variables related to sporting activities (attachment to family, attachment to peers, coaches' input) acting together may add to the expression of positive educational interaction between parents and children in sporting activities. Another new thing is that for the first time in research literature adolescents' attachment to parents is operationalized by two variables (attachment to parents and attachment to peers) reflecting their participation in sporting activities in order to find out, which variable is more important in the period of adolescence. On the practical level the results and conclusions of this dissertation may first of all help managers of sport clubs, organizations, school staff and educators to better understand how parents – by creating positive and supporting relations in sporting activities of their teenage children – may add to the achievement of the goals and objectives and in this way educate democratically minded youth ready to actively engage in social and public life. Secondly, this dissertation is relevant and has a practical value for the promotion of positive development of adolescents and responsible parenting. It opens a new view for professionals (coaches, sport educators, sport psychologists) working with athletes and their parents to the variety of experiences and through the knowledge gained increase the wellness of athletes and their parents. Thus, the clearer aspects of family attachment and experiences of athlete adolescents in their relations with parents may help to improve the skills not only of athlete adolescents but also of their parents and coaches. It should be noted that the findings of this dissertation were implemented in practice – a new intervention programme facilitating the parental involvement in children's sporting activities has been developed. More information about this educational programme is available at www.lisinskiene.com. CONCLUSIONS 1. Scientific literature analysis revealed that parent–child educational interaction in sport is a bi-directional system. Parents influence children: they learn to be emphatic, self-disciplined, self-respected, they build communication skills, and plan their daily routine. Children influence parents because involvement in the child's sport naturally changes parents and modifies their lives: parental daily routine alters, their cognition, knowledge and emotions change, their circle of contacts increases, interpersonal relations with the child, in the family, with other participants in sports also change. Marital relations of parents also alter through the child's participation in sport, some parents start playing sports. Parent–child educational interaction in sport depends on financial and psychological support from parents, the child's physical and emotional security, the coach's positive education strategy, competence and authority. Educational interaction in sport is possible by more active attraction of parents into children's sport; not making pressure on athletic children; motivating them to play sports through psychologically supporting environment; providing continuous training possibilities for coaches. 2. The investigation into the relationship between the adolescents' sporting activities and attachment to family and peers revealed that athlete adolescents' relations with parents are more intensively expressed in all scales: communication, trust and alienation compared to non-athlete adolescents. No relationship was found between adolescents' participation in sport and attachment to peers. 3. Interviews with parents revealed the importance of the coach's role for strengthening parent–child interaction in sport. Parent–child educational interaction in sport depends on the coaching strategy selected by the coach and the degree and form of parental involvement in children's sport. Parents of athlete adolescents acknowledge the benefit of positive coaching and education strategy selected by the coach. This understanding confirms the importance of positive tri-dimensional interaction among parents, children and coaches. However, a phenomenon that has a negative effect on this interaction: parents find it difficult to admit the children's growing attachment to coach. The contraposition to close relations between the child and the coach demonstrated by parents may encourage the alienation between parents and children in sport. 4. Interviews with athlete adolescents revealed that parental involvement into children's sport is more important in the early period of sporting life and becomes less appreciable or unwelcome when children gain sporting experience. In the background of parent–child interrelations in sporting activities adolescents alienation from parents is more common than communication and trust. Alienation of older adolescents from parents in sports has several causes: growing children seek to be independent from their families in sports, some parents behave inappropriately in youth sport and embarrass their children. Interviews with athlete adolescents revealed that some parents demonstrate substandard behaviour in relation to their children, have no loyalty towards other participants of the sporting activity. However, financial support remains and important factor of parental support in all levels of sporting experience. The degree and form of parental involvement into children's sport influences the effectiveness of parent–child educational interaction. The degree and form of involvement chosen by the parents are not always appropriate and encouraging, and not always acceptable to adolescents.

The object of this research is the Zaberezinskis family among the political elite of the Grand Duchy of Lithuania: the association of the family's history (its genealogy, economic, political, foundational activity) with the rest of the environment of the GDL rulers of the Jagiellonian Dynasty. The general backdrop of the political life of the GDL makes it possible to see and evaluate the weight of the Zaberezininkis family among the country's ruling elite. From the late 15th to the middle of the 16th century, the aristocratic authority with its ages-old roots acquired institutional form. Foreseeing the possibility of rulers residing outside the Grand Duchy of Lithuania (as during Kazimierz Jagiellonian's rule), Alexander Jagiellonian's privilege of 6 August 1492 authorized broader prerogatives for the Council of Lords. At the same time, on the eve of the proclamation of the Grand Duke, the summoned parliament initiated the tradition of representation of the nobility. Institutional changes were accompanied by the reception of humanistic ideas, legal culture and political theory, linked to the custom, increasing at the time, of nobility sending their offspring to universities to pursue higher education. The story of the Zaberezinskis family, descendants of Rimvydas, is presented In the context of the formation of the GDL Republic (Respublica Magni Ducatus Lithuaniae), a political nation of descendants of the Romans (as the Lithuanian nobility portrayed themselves). The earliest data on the kin are associated with the times of Sigismund Kęstutaitis, and the latest with those of Sigismund Augustus. Members of the family played a particularly significant role in the history of the Grand Duchy of Lithuania in the times of Kazimierz Jagiellonian and his two sons Alexander and Sigismund the Old, from the 1480s until 1544. Responding to the postulates of the modern science of genealogy, the story of the family is presented according to its different branches. Against the background of key events in Lithuanian history, beginning from Jurgis Rimvydaitis and Jonas Jurgaitis Zaberezinskis, the careers of the latter's children and their descendants, their interrelationships, and factors influencing their careers are analysed. Due to the different status of different members of the family and the different amounts of data available in the sources, the questionnaire applied to different members of the family differs. Jonas Jurgaitis and his son Jonas Jonaitis Zaberezinskis, who reached the highest posts, are the most significant, and the most extensive treatment is given to their biographies. The composition of the landholding and the development of the network of towns are discussed in a separate part of the study. The available data (including property holdings) do not directly confirm a family relationship between the Zaberezinskis and the Manvydas families. No sources have been found in which the Zaberezinskis in any way mention Manvydas or his brother, or a family relationship with them. In the view of the author of this work, the success of Jonas Jurgaitis Zaberezinsky's career can be attributed to his holding the strategic post of Vicar of Polotsk at a key moment, the favour of Lithuanian Grand Duke Alexander and strong personal abilities. In consequence, Jonas Jurgaitis Zaberezinsky proved one of the most prominent personalities on the Council of Lords, achieving the particularly high offices of Voivode of Trakai and Grand Marshall, and personally taking part in the most important events in the interstate relations of the Grand Duchy of Lithuania. For a variety of reasons (often due to early death), the only descendent of Jonas Jurgaitis Zaberezinskis who achieved a significant political career was his son Jonas Jonaitis Zaberezinskis (~1473-1538), who ultimately, like his father, assumed the posts of Voivode of Trakai and Grand Marshall of the Grand Duchy of Lithuania. His relations with the other most influential high-ranking noblemen of the period are considered, especially the meaning of marriages contracted by him and arranged by him for his descendants and relatives. The gathered data regarding the formation and distribution of the family's latifundium show that the most important stage in the formation of the estate was the time of Jonas Jurgaitis Zaberezinskis, although later the family also acquired significant properties through marriage and purchases. A major step in this process was the marriage of Jonas Jurgaitis Zaberezinskis to the daughter, Ona, of Jonas Nasuta, who held large properties in Palenkė (Podlasie). Other ways land was acquired were purchases and gifts of the rulers (Casimir and Alexander). One such event that stands out is Alexander's gift in 1506 of the regions of Alytus and Simnas. Many of the surviving papers written by Jonas Jonaitis Zaberezinskis in the final period of his life, when he resided in Alytus as Keeper of the City and the Region, testify to intense internal colonization of the area of Alytus and Simnas by the Nemunas River. Alytus and Simnas also include the most noteworthy church foundations made by Jonas Jonaitis Zaberezinskis and his family, a clear witness to the founders' piety. As he gave the decisive impulse for Alytus and Simnas to become city-like settlements, he can properly be considered the founder of those cities. The political self-awareness of the Lithuanian aristocracy is best captured by the term from that period "the Republic of the Grand Duchy of Lithuania" (Respublica Magni Ducatus Lithuaniae), as D. Kuolis has accurately observed. The theory of the Roman origins of the Lithuanian nobility, with all its consequences (such as e.g. the rule of law), can be considered the highest peak of the political culture of the ruling elite of the Grand Duchy of Lithuania. In 1525 (well before the Union of Lublin, which is often associated with Lithuanian republican traditions) Albertas Goštautas's memorial to the Grand Duchess Bona associated the notion of nobility with loyalty to the ruler and responsibility for the commonwealth (the republic). Although it can be said that certain Republican ideals drawn from antiquity thrived among the Lithuanian aristocracy, their dominant trait was conservatism (unwillingness to admit lesser nobility to the structures of power). The high-rank nobility clearly recognized the ruler as the head of the political body of the Grand Duchy, and sought for him a crown. The programme for a Kingdom of Lithuania should be linked to the need, fostered by aristocracy, for the GDL to have its own distinct identity, though having a separate ruler was important also for practical reasons: the unquestioned centralized government accelerated the defence mechanisms of the state. A contemporary observer testifies that, when the ruler was absent, the Lithuanian lords "did not know what to do, remained undecided and did nothing." The ruling elite of the Grand Duchy of Lithuania, both in their actions and in what they wrote (in the Lithuanian chronicles and elsewhere), unequivocally showed that no agreements with the Polish Crown bound them. The role of the aristocracy in the political emancipation of the lesser nobility and the importance of the latter for the maturing of the Lithuanian-Polish Union are issues that still require further research. Jonas Jonaitis Zaberezinskis gave some of his nobles personal freedom and economic autonomy, which can be regarded as a precondition for political emancipation.

The object of this research is the Zaberezinskis family among the political elite of the Grand Duchy of Lithuania: the association of the family's history (its genealogy, economic, political, foundational activity) with the rest of the environment of the GDL rulers of the Jagiellonian Dynasty. The general backdrop of the political life of the GDL makes it possible to see and evaluate the weight of the Zaberezininkis family among the country's ruling elite. From the late 15th to the middle of the 16th century, the aristocratic authority with its ages-old roots acquired institutional form. Foreseeing the possibility of rulers residing outside the Grand Duchy of Lithuania (as during Kazimierz Jagiellonian's rule), Alexander Jagiellonian's privilege of 6 August 1492 authorized broader prerogatives for the Council of Lords. At the same time, on the eve of the proclamation of the Grand Duke, the summoned parliament initiated the tradition of representation of the nobility. Institutional changes were accompanied by the reception of humanistic ideas, legal culture and political theory, linked to the custom, increasing at the time, of nobility sending their offspring to universities to pursue higher education. The story of the Zaberezinskis family, descendants of Rimvydas, is presented In the context of the formation of the GDL Republic (Respublica Magni Ducatus Lithuaniae), a political nation of descendants of the Romans (as the Lithuanian nobility portrayed themselves). The earliest data on the kin are associated with the times of Sigismund Kęstutaitis, and the latest with those of Sigismund Augustus. Members of the family played a particularly significant role in the history of the Grand Duchy of Lithuania in the times of Kazimierz Jagiellonian and his two sons Alexander and Sigismund the Old, from the 1480s until 1544. Responding to the postulates of the modern science of genealogy, the story of the family is presented according to its different branches. Against the background of key events in Lithuanian history, beginning from Jurgis Rimvydaitis and Jonas Jurgaitis Zaberezinskis, the careers of the latter's children and their descendants, their interrelationships, and factors influencing their careers are analysed. Due to the different status of different members of the family and the different amounts of data available in the sources, the questionnaire applied to different members of the family differs. Jonas Jurgaitis and his son Jonas Jonaitis Zaberezinskis, who reached the highest posts, are the most significant, and the most extensive treatment is given to their biographies. The composition of the landholding and the development of the network of towns are discussed in a separate part of the study. The available data (including property holdings) do not directly confirm a family relationship between the Zaberezinskis and the Manvydas families. No sources have been found in which the Zaberezinskis in any way mention Manvydas or his brother, or a family relationship with them. In the view of the author of this work, the success of Jonas Jurgaitis Zaberezinsky's career can be attributed to his holding the strategic post of Vicar of Polotsk at a key moment, the favour of Lithuanian Grand Duke Alexander and strong personal abilities. In consequence, Jonas Jurgaitis Zaberezinsky proved one of the most prominent personalities on the Council of Lords, achieving the particularly high offices of Voivode of Trakai and Grand Marshall, and personally taking part in the most important events in the interstate relations of the Grand Duchy of Lithuania. For a variety of reasons (often due to early death), the only descendent of Jonas Jurgaitis Zaberezinskis who achieved a significant political career was his son Jonas Jonaitis Zaberezinskis (~1473-1538), who ultimately, like his father, assumed the posts of Voivode of Trakai and Grand Marshall of the Grand Duchy of Lithuania. His relations with the other most influential high-ranking noblemen of the period are considered, especially the meaning of marriages contracted by him and arranged by him for his descendants and relatives. The gathered data regarding the formation and distribution of the family's latifundium show that the most important stage in the formation of the estate was the time of Jonas Jurgaitis Zaberezinskis, although later the family also acquired significant properties through marriage and purchases. A major step in this process was the marriage of Jonas Jurgaitis Zaberezinskis to the daughter, Ona, of Jonas Nasuta, who held large properties in Palenkė (Podlasie). Other ways land was acquired were purchases and gifts of the rulers (Casimir and Alexander). One such event that stands out is Alexander's gift in 1506 of the regions of Alytus and Simnas. Many of the surviving papers written by Jonas Jonaitis Zaberezinskis in the final period of his life, when he resided in Alytus as Keeper of the City and the Region, testify to intense internal colonization of the area of Alytus and Simnas by the Nemunas River. Alytus and Simnas also include the most noteworthy church foundations made by Jonas Jonaitis Zaberezinskis and his family, a clear witness to the founders' piety. As he gave the decisive impulse for Alytus and Simnas to become city-like settlements, he can properly be considered the founder of those cities. The political self-awareness of the Lithuanian aristocracy is best captured by the term from that period "the Republic of the Grand Duchy of Lithuania" (Respublica Magni Ducatus Lithuaniae), as D. Kuolis has accurately observed. The theory of the Roman origins of the Lithuanian nobility, with all its consequences (such as e.g. the rule of law), can be considered the highest peak of the political culture of the ruling elite of the Grand Duchy of Lithuania. In 1525 (well before the Union of Lublin, which is often associated with Lithuanian republican traditions) Albertas Goštautas's memorial to the Grand Duchess Bona associated the notion of nobility with loyalty to the ruler and responsibility for the commonwealth (the republic). Although it can be said that certain Republican ideals drawn from antiquity thrived among the Lithuanian aristocracy, their dominant trait was conservatism (unwillingness to admit lesser nobility to the structures of power). The high-rank nobility clearly recognized the ruler as the head of the political body of the Grand Duchy, and sought for him a crown. The programme for a Kingdom of Lithuania should be linked to the need, fostered by aristocracy, for the GDL to have its own distinct identity, though having a separate ruler was important also for practical reasons: the unquestioned centralized government accelerated the defence mechanisms of the state. A contemporary observer testifies that, when the ruler was absent, the Lithuanian lords "did not know what to do, remained undecided and did nothing." The ruling elite of the Grand Duchy of Lithuania, both in their actions and in what they wrote (in the Lithuanian chronicles and elsewhere), unequivocally showed that no agreements with the Polish Crown bound them. The role of the aristocracy in the political emancipation of the lesser nobility and the importance of the latter for the maturing of the Lithuanian-Polish Union are issues that still require further research. Jonas Jonaitis Zaberezinskis gave some of his nobles personal freedom and economic autonomy, which can be regarded as a precondition for political emancipation.

The object of this research is the Zaberezinskis family among the political elite of the Grand Duchy of Lithuania: the association of the family's history (its genealogy, economic, political, foundational activity) with the rest of the environment of the GDL rulers of the Jagiellonian Dynasty. The general backdrop of the political life of the GDL makes it possible to see and evaluate the weight of the Zaberezininkis family among the country's ruling elite. From the late 15th to the middle of the 16th century, the aristocratic authority with its ages-old roots acquired institutional form. Foreseeing the possibility of rulers residing outside the Grand Duchy of Lithuania (as during Kazimierz Jagiellonian's rule), Alexander Jagiellonian's privilege of 6 August 1492 authorized broader prerogatives for the Council of Lords. At the same time, on the eve of the proclamation of the Grand Duke, the summoned parliament initiated the tradition of representation of the nobility. Institutional changes were accompanied by the reception of humanistic ideas, legal culture and political theory, linked to the custom, increasing at the time, of nobility sending their offspring to universities to pursue higher education. The story of the Zaberezinskis family, descendants of Rimvydas, is presented In the context of the formation of the GDL Republic (Respublica Magni Ducatus Lithuaniae), a political nation of descendants of the Romans (as the Lithuanian nobility portrayed themselves). The earliest data on the kin are associated with the times of Sigismund Kęstutaitis, and the latest with those of Sigismund Augustus. Members of the family played a particularly significant role in the history of the Grand Duchy of Lithuania in the times of Kazimierz Jagiellonian and his two sons Alexander and Sigismund the Old, from the 1480s until 1544. Responding to the postulates of the modern science of genealogy, the story of the family is presented according to its different branches. Against the background of key events in Lithuanian history, beginning from Jurgis Rimvydaitis and Jonas Jurgaitis Zaberezinskis, the careers of the latter's children and their descendants, their interrelationships, and factors influencing their careers are analysed. Due to the different status of different members of the family and the different amounts of data available in the sources, the questionnaire applied to different members of the family differs. Jonas Jurgaitis and his son Jonas Jonaitis Zaberezinskis, who reached the highest posts, are the most significant, and the most extensive treatment is given to their biographies. The composition of the landholding and the development of the network of towns are discussed in a separate part of the study. The available data (including property holdings) do not directly confirm a family relationship between the Zaberezinskis and the Manvydas families. No sources have been found in which the Zaberezinskis in any way mention Manvydas or his brother, or a family relationship with them. In the view of the author of this work, the success of Jonas Jurgaitis Zaberezinsky's career can be attributed to his holding the strategic post of Vicar of Polotsk at a key moment, the favour of Lithuanian Grand Duke Alexander and strong personal abilities. In consequence, Jonas Jurgaitis Zaberezinsky proved one of the most prominent personalities on the Council of Lords, achieving the particularly high offices of Voivode of Trakai and Grand Marshall, and personally taking part in the most important events in the interstate relations of the Grand Duchy of Lithuania. For a variety of reasons (often due to early death), the only descendent of Jonas Jurgaitis Zaberezinskis who achieved a significant political career was his son Jonas Jonaitis Zaberezinskis (~1473-1538), who ultimately, like his father, assumed the posts of Voivode of Trakai and Grand Marshall of the Grand Duchy of Lithuania. His relations with the other most influential high-ranking noblemen of the period are considered, especially the meaning of marriages contracted by him and arranged by him for his descendants and relatives. The gathered data regarding the formation and distribution of the family's latifundium show that the most important stage in the formation of the estate was the time of Jonas Jurgaitis Zaberezinskis, although later the family also acquired significant properties through marriage and purchases. A major step in this process was the marriage of Jonas Jurgaitis Zaberezinskis to the daughter, Ona, of Jonas Nasuta, who held large properties in Palenkė (Podlasie). Other ways land was acquired were purchases and gifts of the rulers (Casimir and Alexander). One such event that stands out is Alexander's gift in 1506 of the regions of Alytus and Simnas. Many of the surviving papers written by Jonas Jonaitis Zaberezinskis in the final period of his life, when he resided in Alytus as Keeper of the City and the Region, testify to intense internal colonization of the area of Alytus and Simnas by the Nemunas River. Alytus and Simnas also include the most noteworthy church foundations made by Jonas Jonaitis Zaberezinskis and his family, a clear witness to the founders' piety. As he gave the decisive impulse for Alytus and Simnas to become city-like settlements, he can properly be considered the founder of those cities. The political self-awareness of the Lithuanian aristocracy is best captured by the term from that period "the Republic of the Grand Duchy of Lithuania" (Respublica Magni Ducatus Lithuaniae), as D. Kuolis has accurately observed. The theory of the Roman origins of the Lithuanian nobility, with all its consequences (such as e.g. the rule of law), can be considered the highest peak of the political culture of the ruling elite of the Grand Duchy of Lithuania. In 1525 (well before the Union of Lublin, which is often associated with Lithuanian republican traditions) Albertas Goštautas's memorial to the Grand Duchess Bona associated the notion of nobility with loyalty to the ruler and responsibility for the commonwealth (the republic). Although it can be said that certain Republican ideals drawn from antiquity thrived among the Lithuanian aristocracy, their dominant trait was conservatism (unwillingness to admit lesser nobility to the structures of power). The high-rank nobility clearly recognized the ruler as the head of the political body of the Grand Duchy, and sought for him a crown. The programme for a Kingdom of Lithuania should be linked to the need, fostered by aristocracy, for the GDL to have its own distinct identity, though having a separate ruler was important also for practical reasons: the unquestioned centralized government accelerated the defence mechanisms of the state. A contemporary observer testifies that, when the ruler was absent, the Lithuanian lords "did not know what to do, remained undecided and did nothing." The ruling elite of the Grand Duchy of Lithuania, both in their actions and in what they wrote (in the Lithuanian chronicles and elsewhere), unequivocally showed that no agreements with the Polish Crown bound them. The role of the aristocracy in the political emancipation of the lesser nobility and the importance of the latter for the maturing of the Lithuanian-Polish Union are issues that still require further research. Jonas Jonaitis Zaberezinskis gave some of his nobles personal freedom and economic autonomy, which can be regarded as a precondition for political emancipation.

Research problem It has been four decades since conclusion of the Vienna Convention on the law of treaties. The Convention included a provision that a treaty shall be inter-preted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose. The customary status of this rule has been accepted by the International Court of Justice. Disregarding that, some question whether the rules, as opposed to principles, of interpretation are possible (i.e. would that not be better not to reduce them to writing). The International Law Commission itself has com-mented on this. On the other hand, the differences concerning interpretation of treaties were apparent already at the time the treaty was drafted. When the Convention was finally adopted, a few scholars representing the so-called New Haven approach opined that they expected the Convention to fail due to its "insistent emphasis upon an impossible, comformity-imposing textuality". In their view, conclusion of an international agreement was a continuous process of cooperation and collaboration of the parties, which required a much more detailed focus on the intentions of the parties than the Vienna Convention rule of interpretation envisaged. They called for interpretation which would search for genuine shared expectations, together with the complementary appeals for 'supplementing' and 'policing' communications in accordance with overriding community goals. Disregarding these hallmarks, they accepted that the text should remain an important index of party expectations, which they identify as one of the goals of interpretation. In their view, attention to the carefully worked out arrangements of the parties encourages the clarity of expectation, especially when sources of equal credibility give contradictory results concern-ing their expectations. Although the New Haven approach to interpretation of treaties was not included in the Vienna Convention on the Law of Treaties, a form of their reflection could be identified in national law, especially that of continental legal systems. It is agreed that the major difference between common law and conti-nental practice lies in the rules of interpretation: common law is based on a presumption of law, into which statutes are interwoven, hence the practice of drafting statutes in the fullest detail, and the broad assumptions that a statute deals only with those cases which fall within its actual wording. Continental theory, on the other hand, treats statutes as a basis of the law, but these tend to be drafted in a very general and abstract way, leaving it up to the courts to fill in the details by reference to a presumed legislative intention. However, this key difference seems to dissipate, as the common law tends to move away from the purely literal towards the purposive construction of statutory provi-sions, i.e. a new, 'revamped' version of literal rule has developed, which required the general context and purpose to be taken into consideration before any decision is reached concerning the ordinary meaning of statutory words. The continental practice remains consistent on its emphasis on the legislative intention. In the law of contracts this rule turns into a global one: both Lando and UNIDROIT principles of international commercial contracts include a rule of interpretation requiring to determine the common intentions of the parties. This approach finds reflection also in the Civil Code of the Republic of Lithuania, which was drafted on the basis of the UNIDROIT Principles. The International Law Commission returned to the topic of interpreta-tion of treaties thirty years later, in 2000, when it decided to consider the issue of fragmentation of international law and the potential problems it might give rise to. With this purpose in mind in its report on the topic of 2006 the study group has identified four general principles of interpretation of international rules: first, international law should be considered as a legal system, not as a random collection of international rules; second, in applying international law, it is necessary to determine the precise relationship between two or more rules and principles that are both valid and applicable in respect of the whole situa-tion (i.e. to identify whether their relationship is a one of interpretation or con-flict); thirdly, the norms should be interpreted in accordance with the Vienna Convention on the law of treaties, and fourthly, when several norms bear on a single issue, they should be interpreted so as to give rise to a set of compatible obligations. Explaining the latter principle, the Commission, similarly to the New Haven group approach, emphasized the need to take into consideration the community values, i.e. ius cogens and erga omnes, even though continues to recommend to follow the Vienna Convention approach on the ordinary meaning of the terms. Forty years later, it is already possible to consider, whether the New Haven group was correct criticising the Vienna Convention rule of interpreta-tion for its excessive emphasis on text, and how significant is the practical difference between the rule requiring to determine the common intentions of the parties as opposed to the rule, which requires to interpret a treaty in accor-dance with the ordinary meaning of its terms. Also, what is the practical im-pact of these differences on protection of the rights of persons. In order to answer this research question, the focus of the dissertation is on the foreign investment law in the energy sector. The topic is suitable and convenient to consider the impact of the rules of interpretation and the problems posed by fragmentation of international law. Its sources include in-ternational, national, and for the EU countries also EU law, even though the nature of the relationship between EU law and international investment law remains a disputable issue. The energy sector has been chosen in order to evaluate more precisely the impact of the rules of interpretation and fragmenta-tion of international law on the content of the rights of persons and their appli-cation. Research sources The Dissertation analyzes multilateral and bilateral investment trea-ties which are significant for the the protection of investment in the energy sector and the decisions of international investment arbitral tribunals. The ma-jor sources of international investment law are international treaties. The most significant documents for the energy sector currently are the Energy Charter treaty, the ICSID Convention, and the bilateral investment treaties, although national law remains also important for enforcement of arbitral awards and interpretation of state contracts. State contracts also remain significant, be-cause as a rule they include arbitration clauses and stabilization clauses. The latter are particularly common in the energy sector due to its specificity – on the one hand, energy is a heavily politicized sector due to its significance for the development of the economy of a state and both its economic and political stability. Therefore it has a status of a strategic sector, even an issue of national security. This could be observed ever since the beginning of the twentieth century. On the other hand, energy is an infrastructure sector, which requires high investments for development. Not all states are capable to develop this sector by their own financial means, and choose to attract foreign investment. As a result, investment contracts (state contracts) are concluded; they have a status of international commercial contracts, and their parties are free to choose both the applicable law and the means of dispute settlement. The en-ergy contracts as a rule include stabilization clauses, which seek to maintain stable business legal and financial environment for the duration of the contract. Finally, European Union law may also be accepted as a source for in-vestment protection, despite its generalized purposes, which are to achieve the strengthening and convergence of their economies and to establish a monetary and economic union, to implement a common foreign and security policy, including the progressive framing of the common defence policy, and to estab-lish the area of freedom, security and justice. EU law and foreign investment law are still largely conceived as independent and hardly interlinked. However, as integration between the EU member states becomes closer, EU legislation makes an increasing impact also on the specific sectors of the economy, in-cluding the energy sector. Research object The research object of this dissertation are the problems of interpreta-tion and application of law which arise in the resolution of disputes concerning protection of investments in the energy sector between the host states and for-eign investors. They may be grouped into three groups on the basis of the ap-plicable law: 1. The problems of interpretation of international agreements. Both BITs and MITs apply only with respect to investment. ICSID arbitral tribunals can hear only disputes arising directly out of an investment. Disregarding the key role the notion has on the exercise of rights, its meaning remains unclear. The most recent arbitral practice is completely inconsistent on this issue. No less problems are posed by the umbrella clauses, which are included in a large number of BITs and the Energy Charter Treaty, and which requires states to observe obligations they have entered into with an investor. These provisions have been included even in the BITs of 1970s, but in practice they have emerged only recently. The arbitral tribunals differ on whether this provision should be read literaly, or whether its meaning should be restricted. 2. The problems of interpretation of arbitration clauses and invest-ment contracts. This group includes the problems concerning arbitrab

Research problem It has been four decades since conclusion of the Vienna Convention on the law of treaties. The Convention included a provision that a treaty shall be inter-preted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose. The customary status of this rule has been accepted by the International Court of Justice. Disregarding that, some question whether the rules, as opposed to principles, of interpretation are possible (i.e. would that not be better not to reduce them to writing). The International Law Commission itself has com-mented on this. On the other hand, the differences concerning interpretation of treaties were apparent already at the time the treaty was drafted. When the Convention was finally adopted, a few scholars representing the so-called New Haven approach opined that they expected the Convention to fail due to its "insistent emphasis upon an impossible, comformity-imposing textuality". In their view, conclusion of an international agreement was a continuous process of cooperation and collaboration of the parties, which required a much more detailed focus on the intentions of the parties than the Vienna Convention rule of interpretation envisaged. They called for interpretation which would search for genuine shared expectations, together with the complementary appeals for 'supplementing' and 'policing' communications in accordance with overriding community goals. Disregarding these hallmarks, they accepted that the text should remain an important index of party expectations, which they identify as one of the goals of interpretation. In their view, attention to the carefully worked out arrangements of the parties encourages the clarity of expectation, especially when sources of equal credibility give contradictory results concern-ing their expectations. Although the New Haven approach to interpretation of treaties was not included in the Vienna Convention on the Law of Treaties, a form of their reflection could be identified in national law, especially that of continental legal systems. It is agreed that the major difference between common law and conti-nental practice lies in the rules of interpretation: common law is based on a presumption of law, into which statutes are interwoven, hence the practice of drafting statutes in the fullest detail, and the broad assumptions that a statute deals only with those cases which fall within its actual wording. Continental theory, on the other hand, treats statutes as a basis of the law, but these tend to be drafted in a very general and abstract way, leaving it up to the courts to fill in the details by reference to a presumed legislative intention. However, this key difference seems to dissipate, as the common law tends to move away from the purely literal towards the purposive construction of statutory provi-sions, i.e. a new, 'revamped' version of literal rule has developed, which required the general context and purpose to be taken into consideration before any decision is reached concerning the ordinary meaning of statutory words. The continental practice remains consistent on its emphasis on the legislative intention. In the law of contracts this rule turns into a global one: both Lando and UNIDROIT principles of international commercial contracts include a rule of interpretation requiring to determine the common intentions of the parties. This approach finds reflection also in the Civil Code of the Republic of Lithuania, which was drafted on the basis of the UNIDROIT Principles. The International Law Commission returned to the topic of interpreta-tion of treaties thirty years later, in 2000, when it decided to consider the issue of fragmentation of international law and the potential problems it might give rise to. With this purpose in mind in its report on the topic of 2006 the study group has identified four general principles of interpretation of international rules: first, international law should be considered as a legal system, not as a random collection of international rules; second, in applying international law, it is necessary to determine the precise relationship between two or more rules and principles that are both valid and applicable in respect of the whole situa-tion (i.e. to identify whether their relationship is a one of interpretation or con-flict); thirdly, the norms should be interpreted in accordance with the Vienna Convention on the law of treaties, and fourthly, when several norms bear on a single issue, they should be interpreted so as to give rise to a set of compatible obligations. Explaining the latter principle, the Commission, similarly to the New Haven group approach, emphasized the need to take into consideration the community values, i.e. ius cogens and erga omnes, even though continues to recommend to follow the Vienna Convention approach on the ordinary meaning of the terms. Forty years later, it is already possible to consider, whether the New Haven group was correct criticising the Vienna Convention rule of interpreta-tion for its excessive emphasis on text, and how significant is the practical difference between the rule requiring to determine the common intentions of the parties as opposed to the rule, which requires to interpret a treaty in accor-dance with the ordinary meaning of its terms. Also, what is the practical im-pact of these differences on protection of the rights of persons. In order to answer this research question, the focus of the dissertation is on the foreign investment law in the energy sector. The topic is suitable and convenient to consider the impact of the rules of interpretation and the problems posed by fragmentation of international law. Its sources include in-ternational, national, and for the EU countries also EU law, even though the nature of the relationship between EU law and international investment law remains a disputable issue. The energy sector has been chosen in order to evaluate more precisely the impact of the rules of interpretation and fragmenta-tion of international law on the content of the rights of persons and their appli-cation. Research sources The Dissertation analyzes multilateral and bilateral investment trea-ties which are significant for the the protection of investment in the energy sector and the decisions of international investment arbitral tribunals. The ma-jor sources of international investment law are international treaties. The most significant documents for the energy sector currently are the Energy Charter treaty, the ICSID Convention, and the bilateral investment treaties, although national law remains also important for enforcement of arbitral awards and interpretation of state contracts. State contracts also remain significant, be-cause as a rule they include arbitration clauses and stabilization clauses. The latter are particularly common in the energy sector due to its specificity – on the one hand, energy is a heavily politicized sector due to its significance for the development of the economy of a state and both its economic and political stability. Therefore it has a status of a strategic sector, even an issue of national security. This could be observed ever since the beginning of the twentieth century. On the other hand, energy is an infrastructure sector, which requires high investments for development. Not all states are capable to develop this sector by their own financial means, and choose to attract foreign investment. As a result, investment contracts (state contracts) are concluded; they have a status of international commercial contracts, and their parties are free to choose both the applicable law and the means of dispute settlement. The en-ergy contracts as a rule include stabilization clauses, which seek to maintain stable business legal and financial environment for the duration of the contract. Finally, European Union law may also be accepted as a source for in-vestment protection, despite its generalized purposes, which are to achieve the strengthening and convergence of their economies and to establish a monetary and economic union, to implement a common foreign and security policy, including the progressive framing of the common defence policy, and to estab-lish the area of freedom, security and justice. EU law and foreign investment law are still largely conceived as independent and hardly interlinked. However, as integration between the EU member states becomes closer, EU legislation makes an increasing impact also on the specific sectors of the economy, in-cluding the energy sector. Research object The research object of this dissertation are the problems of interpreta-tion and application of law which arise in the resolution of disputes concerning protection of investments in the energy sector between the host states and for-eign investors. They may be grouped into three groups on the basis of the ap-plicable law: 1. The problems of interpretation of international agreements. Both BITs and MITs apply only with respect to investment. ICSID arbitral tribunals can hear only disputes arising directly out of an investment. Disregarding the key role the notion has on the exercise of rights, its meaning remains unclear. The most recent arbitral practice is completely inconsistent on this issue. No less problems are posed by the umbrella clauses, which are included in a large number of BITs and the Energy Charter Treaty, and which requires states to observe obligations they have entered into with an investor. These provisions have been included even in the BITs of 1970s, but in practice they have emerged only recently. The arbitral tribunals differ on whether this provision should be read literaly, or whether its meaning should be restricted. 2. The problems of interpretation of arbitration clauses and invest-ment contracts. This group includes the problems concerning arbitrab