How does the European Court of Human Rights deal with notions, issues and principles of public international law? How is public international law received and applied by the European Court of Human Rights? The different contributions analyse the question Fragmentation or Unity?" in the jurisprudence of the European Court of Human Rights in light of different issues. Topics include the Courts approach to the law of treaties, state responsibility, and state and diplomatic immunity. Likewise, the manner in which the European Court of Human Rights deals with the obligation to not recognize unlawful situations is examined.