As of my last knowledge update in September 2021, the Brunei royal family, specifically the Sultan of Brunei, was known for its substantial wealth. The Sultan of Brunei, Hassanal Bolkiah, has a reputation for living an extravagant lifestyle and possessing vast riches. At that time, his estimated net worth was around $28 billion.
However, please note that financial situations can change over time, and I may not have the most up-to-date information regarding specific individuals or their wealth. It’s always a good idea to consult reliable and current sources for the most accurate and recent financial information.