Colonial Nigeria formed part of the British Empire from the mid-nineteenth century until 1 October 1960, when Nigeria achieved independence. Britain annexed Lagos in 1861 and established the Oil River Protectorate in 1884. British influence in the Niger area increased gradually in the course of the 19th century, but Britain did not effectively occupy the area until 1885. Other European powers acknowledged Britain's dominance over the area at the 1885 Berlin Conference.
From 1886 to 1899, much of the area was ruled by the Royal Niger Company, authorised by charter, and governed by George Taubman Goldie. In 1900, the Southern Nigeria Protectorate and Northern Nigeria Protectorate passed from company hands to the Crown. At the urging of Governor Frederick Lugard, the two territories were amalgamated as the Colony and Protectorate of Nigeria, while each of the three major regions (Northern protectorate, Southern protectorate and the Colony of Lagos) retained considerable regional autonomy. Progressive constitutions after World War II provided for increasing representation and electoral government by Nigerians. The colonial-period proper in Nigeria lasted from 1900 to 1960, after which Nigeria gained its independence.