From 1927 to 1932, wide-reaching negotiations took place between Reza Shah’s court minister, ‘Abdolhossein Khan Teymurtash, and the British Legation in Tehran, the aim of which was to resolve all outstanding issues and to normalize relations between the two countries on the basis of a general treaty. This article examines these Anglo-Iranian negotiations with a particular focus on the thorniest issues—Iran’s territorial claims in the Persian Gulf, particularly its claims to sovereignty over Bahrain, Abu Musa and the two Tunb islands. Though an agreement was never reached, an examination of the content and conduct of these negotiations offers some valuable insights into the unique features of Iranian nationalism and Iranian ambitions in the Persian Gulf during the Reza Shah period.