The British have intervened in the affairs of Brunei on several occasions. Britain attacked Brunei in July 1846 due to internal conflicts over who was the rightful Sultan.
In the 1880s, the decline of the Bruneian Empire continued. The sultan granted land (now Sarawak) to James Brooke, who had helped him quell a rebellion, and allowed him to establish the Raj of Sarawak. Over time, Brooke and his nephews (who succeeded him) leased or annexed more land. Brunei lost much of its territory to him and his dynasty, known as the White Rajahs.
Sultan Hashim Jalilul Alam Aqamaddin appealed to the British to stop further encroachment by the Brookes. The "Treaty of Protection" was negotiated by Sir Hugh Low and signed into effect on 17 September 1888. The treaty said that the sultan "could not cede or lease any territory to foreign powers without British consent"; it provided Britain effective control over Brunei's external affairs, making it a British protected state (which continued until 1984)] But, when the Raj of Sarawak annexed Brunei's Pandaruan District in 1890, the British did not take any action to stop it. They did not regard either Brunei or the Raj of Sarawak as 'foreign' (per the Treaty of Protection). This final annexation by Sarawak left Brunei with its current small land mass and separation into two parts.
British residents were introduced in Brunei under the Supplementary Protectorate Agreement in 1906. The residents were to advise the sultan on all matters of administration. Over time, the resident assumed more executive control than the sultan. The residential system ended in 1959.[77]