Brunei i/bruːˈnaɪ/, officially the Nation of Brunei, the Abode of Peace (Malay: Negara Brunei Darussalam, Jawi: نڬارا بروني دارالسلام, Arabic: دولة بروناي، دار السلام), is a sovereign state located on the north coast of the island of Borneo, in Southeast Asia. Apart from its coastline with the South China Sea, it is completely surrounded by the state of Sarawak, Malaysia, and it is separated into two parts by the Sarawak district of Limbang. It is the only sovereign state completely on the island of Borneo, with the remainder of the island belonging to Malaysia and Indonesia. Brunei's population was 401,890 in July 2011.
The official national history claims that Brunei can trace its beginnings to the 7th century, when it was a subject state of the Srivijayan empire under the name P'o-li. It later became a vassal state of Majapahit empire before converting to Islam in the 15th century. At the peak of its empire, the sultanate had control that extended over the coastal regions of modern-day Sarawak and Sabah, the Sulu archipelago, and the islands off the northwest tip of Borneo. The thalassocracy was visited by the remnants of the Ferdinand Magellan Expedition in 1521 after Magellan was killed some weeks earlier on 27 April of that year and fought the Castille War in 1578 against Spain. Its empire began to decline with the forced ceding of Sarawak to James Brooke and the ceding of Sabah to the British North Borneo Chartered Company. After the loss of Limbang, Brunei finally became a British protectorate in 1888, receiving a resident in 1906. In the years after the Japanese wartime occupation during World War II, it formalised a constitution and fought an armed rebellion. Brunei regained its independence from the United Kingdom on 1 January 1984. Economic growth during the 1970s and 1990s, averaging 56% from 1999 to 2008, has transformed Brunei Darussalam into a newly industrialised country.
Brunei has the second highest Human Development Index among the South East Asia nations after Singapore, and is classified as a developed country. According to the International Monetary Fund (IMF), Brunei is ranked 5th in the world by gross domestic product per capita at purchasing power parity. The IMF also states in a 2011 estimate that Brunei was one of two countries (the other being Libya) with their public debt at 0% of the national GDP. Forbes also ranks Brunei as the fifth richest nation out of 182 nations due to its extensive petroleum and natural gas fields.