Lagos was annexed by the British in 1861. Lagos was a city-state in what is now Nigeria, and it was an important center of trade and commerce in West Africa. In 1861, the British declared Lagos a British protectorate, which meant that the city came under British control and was no longer an independent state. The annexation of Lagos marked the beginning of British colonial rule in Nigeria, and it had a significant impact on the political, economic, and social development of the region.