The British penetration of Nigeria met with various forms of resistance throughout the country. In the south, the British had to fight many wars, in particular the wars against the Ijebu (a Yoruba group) in 1892, the Aro of Eastern Igboland, and, until 1914, the Aniocha of Western Igboland. In the north many emirates did not take military action, but the deposed caliph, Atahiru I, rebelled in 1903. Many Muslims also resorted to migration as a from of resistance, a tactic known as the hijra, in which those perceived as infidels are avoided.
Resistance was strong in western Igboland where a series of wars were waged against the British. The Ekumeku, who were well organized and whose leaders were joined in secrecy oaths, effectively utilized guerrilla tactics to attack the British. Their forces, which were drawn from hundreds of Igbo youth from all parts of the region, created many problems for the British, but the British used forceful tactics and heavy armaments (destroying homes, farms, and roads) to prevail. The Ekumeku, however, became a great source of Igbo nationalism.
For instance, one of the many informants I interviewed on the origins of the Ekumeku war--a war of resistance fought by the west-Niger Igbo against the British for some thirty years (Ohadike, Ekumeku)--thought Benin had a great deal to do with colonial policy at the time.
Ohadike, Don C. The Ekumeku Movement: Western Igbo Resistance to the British Conquest of Nigeria, 1883-1914. Athens: Ohio UP, 1991.