Brunei, independent Islamic sultanate on the northern coast of the island of Borneo in Southeast Asia. It is bounded to the north by the South China Sea and on all other sides by the East Malaysian state of Sarawak, which also divides the state into two disconnected segments of unequal size. The western segment is the larger of the two and contains the capital city of Bandar Seri Begawan. Brunei achieved independence in 1984, after having been a British protectorate since 1888. It is a member of the Commonwealth and ASEAN (Association of Southeast Asian Nations).
In 1959 Brunei became a self-governing state and adopted a constitution, although the British retained jurisdiction over foreign policy, defense, and internal security. Limited attempts at elected representative government under this constitution were abandoned by 1970. After Brunei attained full independence in 1984, an Islamic sultanate was established, and the constitution—while retained—underwent significant amendment.