HMS Defence was a 74-gun Bellona-class third-rate ship of the line of the Royal Navy, built by Israel Pownoll and launched on 31 March 1763 at Plymouth Dockyard. She was one of the most famous ships of the period, taking part in several of the most important naval battles of the French Revolutionary and Napoleonic wars. In 1811 she was wrecked off the coast of Jutland with the loss of almost her entire crew.

The Battle of Cape St. Vincent was a naval battle that took place off the southern coast of Portugal on 16 January 1780 during the American Revolutionary War. A British fleet under Admiral Sir George Rodney defeated a Spanish squadron under Don Juan de Lángara. The battle is sometimes referred to as the Moonlight Battle because it was unusual for naval battles in the Age of Sail to take place at night. It was also the first major naval victory for the British over their European enemies in the war and proved the value of copper-sheathing the hulls of warships.