Sometime in 1827, Burungai Sonko, the king of Barra, decided to abrogate the Ceded Mile Treaty of 1826. The king came to regret the loss of his customs revenues resulting from the treaty and, pressured by his advisors, adopted an anti-British attitude. Because of actions against Bathurst traders in Niumi, the British suspended their annual payments to the king in 1830. His attitude, and the unwise action of British merchants and African traders in Bathurst, led to war. Another contributing factor and possible provocation was British Commodore Charles Bullin's decision to start building a fort (Fort Bullen) at Barra Point. A number of incidents culminated in the Barra War.
The war began on 22 August 1831 as a result of an incident at the settlement near Fort Bullen. Two intoxicated residents of Essau (the Barra capital) demanded rum and shot a musket at the canteen keeper (but missed) before leaving because an alarm was sounded. The British then formed an armed party that went to Essau to apprehend the two men. After firing on Essau, a Barra force emerged that greatly outnumbered the British and forced their retreat. British losses included 23 soldiers killed as well as a number of civilians. Sonko's forces pursued the British and attacked Fort Bullen and forced the British detachment there to flee to Bathurst. For a time, it appeared that the British would be driven out of Barra and the Ceded Mile, and Bathurst was also believed to be threatened. However, it was soon evident that Barra forces had never really contemplated an attack upon Bathurst. At most they wanted to keep the British out of the Ceded Mile. It is possible that the British bombardment of Essau had deterred the Barra from continuing the offensive across the river.
British reinforcements from Sierra Leone arrived on 5 November 1830. Two days later they embarked for a counterattack and regained the fort (possibly on 11 November 1830). The French at Goree, who were keen to protect the interests of their settlement at Albreda, had dispatched a warship and troops to aid the British. Although Sonko's military forces achieved a number of military successes against combined British and French forces, which were unable to capture the village of Essau (bombarded again about 17 November 1830), his subjects suffered heavily from the war. Fighting continued until 5 January 1832, when Sonko was forced to sign a humiliating treaty with Lieutenant Governor George Rendall. Sonko not only reconfirmed the 1826 treaty but also agreed to indemnify the residents of Barra Point and Dog Island for any losses they had experienced and hand over military ordinance to the British; it was also agreed that the lieutenant governor would be asked to give his consent before a new king was chosen.