Anglo-Spanish War (1796-1802). Attack on Puerto Rico (1797). By the Treaty of San Ildefonso in 1796, Spain became an enemy of Great Britain. The British sent a fleet to the Caribbean to invade the islands of Trinidad and Puerto Rico, commanded by Admiral Henry Harvey. They achieved the surrender of Trinidad but were defeated in Puerto Rico. Lieutenant-General Sir Ralph Abercromby invaded the island of Puerto Rico which was defended by the Spanish forces led by Ramon de Castro and the capital's militia commanded by Rafael Conti. Defeat of the British in Puerto Rico during the Battle of San Juan (17 April-2 May, 1797). Engraving by Villegas. Historia del Levantamiento, guerra y revolucion de Espana by the Conde de Toreno. Madrid, 1851.