This work reassesses the doctrine, and present-day status, of historic waters in the law of the sea, particularly in the light of the most recent decisions of the International Court of Justice which have referred to the topic and in the United States, such as Alaska v. US(2005) in which the author acted as expert witness for the US federal Government. The latter case forms a continuous theme throughout the book. Detailed and critical examination is made of the alleged rules in international customary law, including matters such as burden of proof.