State immunity is a rule of international law aimed at facilitating the performance of State functions by preventing the State from being sued in foreign courts. Aimed as it is at the conduct, specifically the abstention, of those courts, it depends substantially on their law and procedural rules conforming with international requirements. Correspondingly the law of State immunity developed primarily through domestic case law and legislation, with limited treaty practice. Only on 2 December 2004 did the General Assembly adopt the UN Convention on Jurisdictional Immunities of States and Their Property, based on the International Law Commission’s lengthy work on the topic.1 Xiaodong Yang underscores the importance of the Convention, referring to it as ‘an epoch-making document’ marking ‘the final establishment of restrictive immunity as the prevailing doctrine in international law’. The book presents a comprehensive overview of the development of the law and doctrine of State immunity, trying to ‘delineate how the law of State immunity has come to be what it is, and what it is that it has become’. This is done through a systematic examination of over 2,000 cases decided over two centuries, combined with an analysis of treaties, national legislation, government statements, discussions in international organizations, and writings of scholars. The strength of the work is very much in the detailed analysis of the extensive caselaw, as well as of the literature,which he does with great vigour and capacity for legal analysis