British colonization in western Africa didn’t really begin until after the British Parliament prohibited British subjects from participating in the slave trade, and in 1833 and in 1843, totally eliminating slavery throughout the British Empire. British influence in the Nigeria area increased gradually over the 19th century with the establishment of a Colony in Lagos in 1862 and the creation of the United African Company (later the Royal Niger Company) in 1879 to develop the Niger basin.
After the Berlin Conference, Britain formalized the Oil Rivers Protectorate, which included the Niger Delta and extended eastward to Calabar, where the British consulate general was relocated from Fernando Po. The primary purpose was to control trade coming down the Niger River. As a protectorate, the new territory didn’t have the full status of a colony, but remained under the jurisdiction of the Foreign Office.
The expansion into the territory was a series of diplomatic treaties and bloody battles, which ultimately subdued most of the local tribes. In August 1891, the British Government established a Consular Administration over the Oil Rivers Protectorate, consisting of six consular river districts.
In 1893 the territory was renamed Niger Coast Protectorate, and expanded to include the region from Old Calabar to Lagos Colony and Protectorate, and northward up the Niger River as far as Lokoja, the headquarters of the Royal Niger Company.
As development proceeded in Nigeria, it soon became obvious that the practice of managing territories through chartered companies could no longer compete with the Government run colonies of the French or Germans. Therefore, the Britain cancelled the charter for the Royal Niger Company for the sum of £865,000 and rights to half the mining revenue for 99 years. On 1 Jan 1900, the territories of the Niger basin were transferred to the British government and the Protectorates of Northern Nigeria and Southern Nigeria were formed.