Brunei–Malaysia border which are defined by agreements, from west to east, are as follows: Brunei and Malaysia in an Exchange of Letters on 16 March 2009, agreed to affirm the five agreements. The two countries also agreed to use the watershed principle to determine the remaining undelimited portions of the border. Brunei's maritime boundary with Malaysia until the 100 fathom isobath was inherited from the Sarawak (Definition of Boundaries) Order in Council 1958 No 1518 and the North Borneo (Definition of Boundaries) Order in Council 1958 No 1517, both of which defined the boundary between Brunei on the one hand, and Sarawak
Brunei–Malaysia border World War II, joined Malaysia on 16 September 1963. Brunei remained a British Protectorate until 1984 when it gained independence. Brunei and Malaysia have had long standing disputes over land and maritime territories. However, due to the cultural ties between the two countries, the disputes have always been low-key and deemed too sensitive to be discussed openly. The main land dispute was over the district of Limbang which has been controlled by Sarawak since 1890, while the dispute over maritime territory involved virtually the entire deep sea section of the South China Sea claimed by Brunei which Malaysia asserted as