HM Hajji Hassanal Bolkiah Mu’izzaddin Waddaulah became the 29th Sultan of Brunei following his father’s abdication in 1967. He became Prime Minister following independence from the UK in 1984. This makes him both the world’s longest-reigning current monarch and the longest-serving current head of state. He is also one of the welathiest people in the world with a net worth of $30 billion. His official residence has over 1,800 rooms and he maintains a car collection in the thousands. He owns many properties (via the Brunei Investment Authority) in the UK including the famous Dorchester Hotel.