HMS Cambrian was a Royal Navy 40-gun fifth-rate frigate. She was built and launched at Bursledon in 1797 and served in the English Channel, off North America, and in the Mediterranean. She was briefly flagship of both Admiral Mark Milbanke and Vice-Admiral Sir Andrew Mitchell during her career, and was present at the Battle of Navarino. Cambrian was wrecked off the coast of Grabusa in 1828.

The Battle of Navarino was a naval battle fought on 20 October 1827, during the Greek War of Independence (1821–29), in Navarino Bay, on the west coast of the Peloponnese peninsula, in the Ionian Sea. Allied forces from Britain, France, and Russia decisively defeated Ottoman and Egyptian forces which were trying to suppress the Greeks, thereby making Greek independence much more likely. An Ottoman armada which, in addition to Imperial warships, included squadrons from the eyalets of Egypt and Tunis, was destroyed by an Allied force of British, French and Russian warships. It was the last major naval battle in history to be fought entirely with sailing ships, although most ships fought at anchor. The Allies' victory was achieved through superior firepower and gunnery.