United States. Central Intelligence Agency, The 2001 CIA World Factbook
“ The Sultanate of Brunei's heyday occurred between the 15th and 17th centuries, when its control extended over coastal areas of northwest Borneo and the southern Philippines. Brunei subsequently entered a period of decline brought on by internal strife over royal succession, colonial expansion of European powers, and piracy. In 1888, Brunei became a British protectorate; independence was achieved in 1984. Brunei benefits from extensive petroleum and natural gas fields, the source of one of the highest per capita GDPs in the less developed countries. ”
