The Sultanate of Brunei cedes Sarawak to the United Kingdom.

The Raj of Sarawak, also State of Sarawak, located in the northwestern part of the island of Borneo, was an independent state that later became a British Protectorate in 1888. It was established as an independent state from a series of land concessions acquired by an Englishman, James Brooke, from the Sultan of Brunei. Sarawak received recognition as an independent state from the United States in 1850, and from the United Kingdom in 1864. The area now forms the Malaysian state of Sarawak.

Following recognition, Brooke expanded the Raj's territory at the expense of Brunei. Several major rebellions occurred against his rule, causing him to be plagued by debt incurred in countering the rebellions, and the sluggish economic situation at the time. His nephew, Charles Brooke, succeeded James and normalised the situation by improving the economy, reducing government debts and establishing public infrastructure. In 1888, the Raj acquired protectorate status from the British Government whilst avoiding annexation.

To gear up economic growth, the second Rajah encouraged the migration of Chinese workers from China and Singapore to work in the agricultural fields. With proper economic planning and stability, Sarawak prospered and emerged as one of the world's major producers of black pepper, in addition to oil and the introduction of rubber plantations. He was succeeded by his son Charles Vyner Brooke but World War II and the arrival of Japanese forces ultimately brought an end to the Raj and the Protectorate administration, with the territory placed under a military administration on the Japanese capitulation in 1945, and ceded to Britain as its last acquisition as Crown Colony in 1946, against the Atlantic Charter.

In the Bruneian history, the Sultanate of Brunei (Jawi: كسلطانن بروني) or simply Brunei ( broo-NY), was a Malay sultanate, centred in Brunei on the northern coast of Borneo island in Southeast Asia. Brunei became a sovereign state around the 15th century, when it grew substantially since the fall of Malacca to the Portuguese, extending throughout coastal areas of Borneo and the Philippines, before it declined in the 17th and 18th centuries.The first ruler or sultan of Brunei was a Muslim. It became a British protectorate in the 19th century.