The fishing and salt-making peoples of the Niger Delta creeks, divided into some forty-three ibe ('clans') and never unified into a single state. The eastern delta ibe threw up the famous trading city-states - Bonny is already on the map - but the central and western delta stayed village-based, which is why the mangrove maze reads blank in this atlas even at 1700.
Not an ending: the Oil Rivers / Niger Coast Protectorate (1884-1900) and then the Protectorate of Southern Nigeria absorbed the delta, and the Ijaw envelope hands over to Colonial Nigeria in 1900. The Ijaw are Nigeria's fourth-largest people today, with their own states of Bayelsa and Rivers.
The standard history of the Ijo/Ijaw delta, built from ibe oral traditions - polity-specific, not a survey.
The classic account of how delta communities met the Atlantic trade and the British consuls who ended their autonomy.