This article has concentrated on the efforts made by the British colonial regime in Northern Nigeria to suppress the slave trade. It has shown that the slave trade disappeared gradually, in three phases. The first extended from 1900 to about 1908, the second lasted until about 1919, while the third continued until the disappearance of the slave trade at the end of the 1930s. The task of suppression was carried out by a variety of means: military, including the patroling of trade routes and policing of strategic locations; political and diplomatic, involving co-operation with other colonial powers in the area; and judicial, including arrest, prosecution and punishment of offenders. In all these efforts the colonial administration received assistance from the Native Authorities; by the third phase these Authorities and the Native Courts were the most active forces against slaving. The slave trade dealt to a very significant extent in children. In the environment in which the trade was conducted the dealers developed a range of tricks and subterfuges to evade detection by the law enforcement agencies. The long borders which the agencies had to patrol, the manpower problems which they faced, and the relative ease with which slaves could be obtained in times of adversity combined to make the struggle against slaving a protracted one. Time was not, however, on the side of the traders. Improvements in communications, a stronger administration, the growing effectiveness of patrols, and the deterrent effects of judicial action cut into and finally eliminated the slave trade.