On 31 August 1795 Fort Ostenburg, the principal fortress of the port of Trincomalee on the island of Ceylon (present-day Sri Lanka), was taken by British forces.

On 23 July 1795 a squadron under Commodore Peter Rainier consisting of Suffolk, Hobart, Centurion, Diomede, with troop-transports, and sailed for Ceylon to take Trincomalee and other Dutch settlements on Ceylon. On 2 August 1795 Diomede, with a transport brig in tow, struck on a sunken rock and sank. She went down with all her stores on board but boats from the squadron saved her crew.

Although the loss of Diomede delayed the landing by a day, on 31 August the British captured Fort Ostenburg and with it complete control of Trincomalee. The British would go on to capture other Dutch settlements in India and Ceylon, but denying Trincomalee to the French was the most important objective. The British held Trincomalee until Sri Lanka's independence in 1948.