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–Indonesia relations defence, transnational crimes, education, youth, culture and people-to-people contacts. Both Brunei and Indonesia have many common characteristic traits, these include common frames of reference in history, culture and religion. Their national languages; Indonesian language and Malay language are closely related. The majority of the population of both nations were of Austronesian ancestry or of the Malay race, with significant Malay culture shared among them. Both nations are Muslim majority countries, members of ASEAN and APEC, and also members of the Non-aligned Movement, and Organisation of Islamic Cooperation. Relations between Indonesia and Brunei has been established since 14th century or perhaps