The San Agustín was a 74-gun ship of the line built at the royal shipyard in Guarnizo (Santander) and launched in 1768. She was captured by Portugal in 1776, but returned the following year. In January 1780, during the American War of Independence, she was part of a squadron of 11 of the line under command of Admiral Don Juan de Lángara left on patrol off Cape St. Vincent to intercept an expected British convoy for Gibraltar. But when the British fleet under Sir George Rodney appeared, it greatly outnumbered the Spanish squadron with 18 ships of the line. The result was the Battle of Cape St. Vincent (1780), off the stormy, dark cliffs of Cape Santa María through the afternoon and evening of 16 January 1780. Six Spanish ships of the line were captured and one destroyed. The San Agustín and