Sokoto is the headquarters and capitol of the Fula Sultan, or Emperor, who formerly ruled nearly all of British Nigeria. Sokoto is a major city located in the extreme northwest of Nigeria, near the confluence of the Sokoto River and the Rima River. From the book Britain across the seas: Africa: a history and description of the British Empire in Africa, by Johnston, Harry Hamilton, Sir (1858-1927), published in 1910 in London by National Society's Depository.