The importance of the Arabs as traders in the Indian Ocean by the 12th century may partly explain why the last Buddhist king of Maldives, Dhovemi, converted to Islam in the year 1153 (or 1193). Adopting the Muslim title of Sultan Muhammad ibn Abdullah, he initiated a series of six Islamic dynasties that lasted until 1932 when the sultanate became elective. The formal title of the sultan up to 1965 was, "Sultan of Land and Sea, Lord of the twelve-thousand islands and Sultan of the Maldives" which came with the style "Highness".