In 1927, Rezā Shāh, then Shah of Iran, demanded sovereignty over Bahrain in a letter to the League of Nations, a move that prompted Belgrave to undertake harsh measures including encouraging conflicts between Shia and Sunni Muslims in order to bring down the uprisings and limit the Iranian influence. Belgrave even went further by suggesting to rename the Persian Gulf to the "Arabian Gulf"; however, the proposal was refused by the British government. Britain's interest in Bahrain's development was motivated by concerns over Saudi and Iranian ambitions in the region.