These additional conflicts around the globe with France and Spain strained Britain's resources for the war in America. The French blockaded Barbados and Jamaica, to damage British trade. The British defeated a French naval force on December 15 and captured St. Lucia. But in 1779, the French began capturing British territories, seizing St. Vincent and Grenada. Britain lost the Battle of Grenada badly in 1779. France and Spain failed to invade England, but a Franco-Spanish fleet decisively defeated a large British convoy bound for the West Indies off the Azores. The defeat was catastrophic for Britain. Spain failed to capture the British naval station at Gibraltar, but the British blockade of Spain and France proved ineffective.