Ramona Pedretti offers, for the first time, a comprehensive assessment of the rules of customary international law relating to immunity of Heads of State and other State officials in the context of crimes pursuant to international law and their relationship with core principles of international law. The book gives the reader a full picture of this topical issue which is located at the heart of today's development of international law. It contains an in-depth evaluation of a vast amount of relevant material, ranging from domestic laws to judicial decisions of domestic and international courts. The fact that the International Law Commission is deliberating the issue with a view to drafting an international treaty underscores the book's importance and timeliness.