There are currently three regional human rights courts active on three continents. The Inter-American Court of Human Rights and the European Court of Human Rights are already well-established courts within their regional frameworks, whereas the African Court of Human and Peoples’ Rights only started issuing judgments in the last decade. Operating in different contexts, the three courts are now engaged in a continuous development of their case law to fulfil their task of protecting human rights. The question arises as to what extent these regional courts refer to the jurisprudence of each other, and that of other international courts, as part of their judicial reasoning. The use of external decisions in the case law of these regional courts is an example of judicial borrowing. Whereas legal mechanisms facilitate this practice, contextual factors shape it. This thesis unravels the role of judicial borrowing in the development of the courts’ jurisprudence. Thus, it assesses both the authority of specific actors in the development of international human rights law, and the institutional contexts surrounding these courts. The research highlights the interplay between the internal structures of the regional systems and the external international legal sphere. The thesis’ methodology builds on the premise that international law is best understood by combining the internal doctrinal study of the law with the study of external, contextual factors. The combined study of the internal and external perspectives reveals the practice of international law and its changes over time. Thus, the study is supplemented by a citation network analysis of the reference to external judicial decisions by each of the courts. The thesis shows the evolving patterns and relationships formed by the citation practices of the three regional human rights courts, and thus provides a novel and empirical understanding of the interaction between the regional human rights courts.