British protectorate over the eastern Niger Delta trading states (Bonny, Opobo, Old Calabar and others), declared as the Oil Rivers Protectorate in 1884-85 to regulate the palm-oil trade and renamed Niger Coast Protectorate on 12 May 1893.
Merged on 1 January 1900 with the Royal Niger Company's territories to form the Protectorate of Southern Nigeria, an ancestor of Colonial Nigeria.
The foundational history of the Niger Delta city-states (Bonny, Opobo, Calabar) and the British trade politics that produced the Oil Rivers Protectorate in 1884.
Broad context for the Berlin-Conference-era declaration of the protectorate.