Sultanate of Kedah كسلطانن قدح Kesultanan Kedah 1136–1941 1945–1946 1948–today Flag Coat of arms Kedah in present-day Malaysia Status Independent (1136-1909) Protectorate of the United Kingdom (1909-1941; 1945-1946) Capital Alor Setar Common languages Malay Kedah Malay English Chinese Tamil Aslian Religion Sunni Islam Sultan • 1136-1179 Mudzaffar Shah I (first) • 2017-present Sallehuddin Current Sultan Advisor • 1909–1915; 1918–1919 George Maxwell Historical era Early modern period • Conversion to Islam 1136 (882 years ago) • Golden Age 1735 • Anglo-Siamese Treaty of 1909 9 July 1909 • Japanese occupation 16 February 1942 • Annexed by Thailand 18 October 1943 • Japanese surrender; returned to United Kingdom 14 August 1945 • Added into Malayan Union 31 March 1946 Currency Native gold and silver coins Straits dollar (until 1939) Malayan dollar (until 1953) Preceded by Succeeded by Kedah Kingdom Srivijaya Syburi Malayan Union Kedah Today part of Malaysia 1 Remains as capital until today 2 Malay using Jawi (Arabic) script