The British led series of military campaigns to enlarge its sphere of influence and expand its commercial opportunities. The superior weapons, tactics and political unity of the British are commonly given as reasons for their decisive victory. In 1892, the British forces set out to fight the Ijebu Kingdom, which had resisted missionaries and foreign traders. The legal justification for this attack was a treaty signed in 1886, when the British had interceded as pacemakers to end the Ekitiparapo war, which imposed free trade requirements and mandated that all parties should continue to use the British as intermediaries. Although the Ijebu had some weapons, they were still defeated by the British machine guns called “Maxim guns”. The British went on to conquer the rest of Yorubaland, which had been weakened by 16 years of civil war. By 1893, most of the other political entities in Yorubaland recognized the practical necessity of signing another treaty with the British, which directly merged them with the protectorate of Lagos.

In 1896-1897, the forces of the Niger Coast Protectorate fought with the remnant forces of the Benin Kingdom. Following the defeat of Consul General James R. Philips, a larger retaliatory force captured Benin City and drove Ovonramwen, the Oba of Benin, into exile. The British had difficulty in conquering Igboland, which had no centralised political organization. In the name of liberating the Igbos from the Aro Confederacy, the British launched the Anglo-Aro War of 1901-1902. Despite conquering villages by burning houses and crops, maintaining political control over the Igbo remained elusive. The British forces began annual pacification missions to convince the locals about British supremacy.

A campaign against the Sokoto Caliphate began in 1900 with the creation of the Protectorate of Northern Nigeria, under the direction of Governor Frederick Lugard. The British conquered Kano, in 1903. Deadly battles broke out sporadically between the British and some local communities throughout 1906. The Colonial Office allowed Lugard’s expeditions to continue because they were framed as retaliatory. The true motive of British conquest of different Nigerian areas was declared in Lugard’s address to the leaders of conquered Sokoto, on 15th February 1903. He said, the British came to govern the people and control their resources.