Possible Clues:

• Tea approaching for audience in Sultan's place
• It's sultan is immensely rich
• Book published that is about part of Borneo
• North Borneo sultanate
• Career that's overturned supporting British state
• Country character of yesteryear in small piece (not leader in Times)
• Country Britain governed that is overthrown
• Country on Borneo
• Bandar Seri Begawan is its capital
• Rich sultanate in the South China Sea