Nana Olomu inherited the Governorship of the Benin River from his father Olomu in 1883 and built Ebrohimi into the largest fortified town in the western Niger Delta — a complex of creeks, stockades, war-canoes and barracoons commanding the Ethiope and Warri rivers and the entire Itsekiri palm-oil and rubber trade with the European hulks at Bobi.
The Oil Rivers Protectorate was upgraded to the Niger Coast Protectorate in 1893 and Sir Claude MacDonald instructed his Vice-Consul Ralph Moor to break the Itsekiri middleman system. Moor demanded Nana dismantle Ebrohimi's defences and admit British firms to the upper Ethiope. Nana refused and reinforced the stockade with 106 cannon bought from Liverpool gunrunners.
On 25 August 1894 Rear-Admiral Frederick Bedford brought HMS Philomel, Widgeon, Alecto and Phoebe up the Benin River. The bombardment lasted a month; Ebrohimi fell on 25 September 1894 after the Itsekiri exhausted their powder. An estimated 200 Itsekiri were killed; Nana escaped through the creeks to Lagos, surrendered to Governor Gilbert Carter, was tried by a Consular Court at Old Calabar and deported to Accra. He was allowed to return to Koko in 1906 and died there in 1916. Ebrohimi was razed; the Itsekiri Governorship of the River was abolished; the entire palm-oil trade of the western Delta passed to the British firms within five years.