What European country did the sultanat Brunei gain its independence from in 1984?

Explanation

The Sultanate of Brunei is a country on the island of Borneo in South East Asia. Brunei is rich on oil, and because the country lives off the oil taxes there are no income taxes. The capital is called Bandar Seri Begawan. Around 370,000 people live in the country which covers an area of 5770 km². Brunei gained independence from Britain in 1984.