20 Dollars - Hassanal Bolkiah Coronation Jubilee

Issued to mark the 25th anniversary of Sultan Hassanal Bolkiah's accession, this coin commemorates a reign that began in 1967 when he was just 21 — inheriting the sultanate from his abdicating father, Omar Ali Saifuddien III, who remained a formidable political presence behind the throne for years afterward. Brunei's oil revenues had by 1988 made the Sultan one of the wealthiest individuals on earth, a fact that lent these commemorative issues something of an awkward grandeur.

Struck to crown silver standard, the series was produced in limited numbers for collectors rather than circulation, consistent with Brunei's practice of issuing collector coinage through the Brunei Currency Board.