Heinz A. Richter's new study sheds light on the importance of the Bosporus and the Dardanelles before and during the First World War. From the development of Anglo-Russian relations to the start of the war and Turkey's entry into it, the role of the Straits in the struggle for Constantinople is examined. The detailed account of the political maneuvering of the powers involved around the Battle of Gallipoli is based on previously unevaluated Russian files and offers a new and comprehensive insight into the history of the Straits issue in the international politics of the early 20th century.