Lagos Colony was a
British colonial possession centred on the port of
Lagos in what is now southern
Nigeria. Lagos was annexed on 6 August 1861 under the threat of force by Commander Beddingfield of HMS Prometheus who was accompanied by the Acting British Consul,
William McCoskry.
Oba Dosunmu of Lagos (spelled "Docemo" in British documents) resisted the cession for 11 days while facing the threat of violence on Lagos and its people, but capitulated and signed the
Lagos Treaty of Cession. Lagos was declared a colony on 5 March 1862. By 1872 Lagos was a cosmopolitan trading center with a population over 60,000. In the aftermath of prolonged wars between the mainland
Yoruba states, the colony established a protectorate over most of
Yorubaland between 1890 and 1897. The colony and protectorate was incorporated into Southern Nigeria in February 1906, and Lagos became the capital of the protectorate of Nigeria in January 1914. Since then, Lagos has grown to become the largest city in West Africa, with an estimated metropolitan population of over 9,000,000 as of 2011.