Harold Beken Thomas (1888-1971) entered the Colonial Service in 1911 as a cadet in the Land and Survey Department in Uganda. He spent nearly thirty years in Uganda, retiring as Director of Surveys in 1940. During this time, he developed an extensive knowledge of Uganda and an interest in East Africa in general. He contributed articles, notes and reviews to the 'Uganda journal', mainly on historical subjects, and also provided editorial assistance. He was a leading figure in the Royal Commonwealth Society's development of a 'Dictionary of East African biography', in which he cooperated with his old friend Sir John Gray. Thomas served as Vice President of the Uganda Society and of the Church Missionary Society. He died on 12 August 1971.