Witu had suffered repeated raids by the Sultanate of Zanzibar to capture slaves, and the Sultan in 1885 formally requested and got German protection. Witu was declared a British Protectorate on 18 June 1890. After armed protests, the British deposed Sultan Fumo Bakari ibn Ahmad and, in 1893, hoisted a new flag: a plain red flag, like the flag of Zanzibar, of which Witu was made a vassal, but with a small Union Jack in the centre.