The Aden Protectorate ( ) was a British protectorate in southern Arabia which evolved in the hinterland of the port of Aden and in the Hadramaut following the conquest of Aden by Great Britain in 1839, and it continued until the 1960s. In 1940 it was divided for administrative purposes into the Western Protectorate and the Eastern Protectorate. Today the territory forms part of the Republic of Yemen.