https://en.wikipedia.org/wiki/BruneiOr to give its full name 'Nation of Brunei, the Abode of Peace' (yes, really). This is one of those small Asian states (Population: 415,717) whose continued existence is due to the wheeling and the dealing nature of the British Empire and their infinite tolerance of aristocratic monarchs and related feudal grandeur (see also, The Middle East). This was after the British had reduced the state from one which controlled most of Northern Borneo to one which takes up a small harbour and hinterland on the north coast that it does today. Since independence, which occurred only in 1984, it has become a very wealthy petro-state. The Sultan of Brunei is regularly cited as among the wealthiest men in the world. He was educated at Sandhurst because of course he was. The country is strongly Islamic and Malay speakers make the majority. Although, given that this is South-East Asia, there is a strong overseas Chinese presence and also many European expats out to make money and probably belittle the locals. There are also non-Malay Bornean ethnicities in what passes for the Bruneian interior. Yes, Bruneian is what you call someone from Brunei.
Below is a map of Borneo in 1850 showing roughly the area controlled by Brunei
