This was an epic four-year attempt by the combined forces of Spain and France to capture Gibraltar from the British during the American War of Independence. It began June 24, 1779 and ended February 7, 1783 as a decisive British victory at great cost.
The defence of Gibraltar under General George Augustus Eliott with a small British force inspired Great Britain at the heels of its defeat in the American Revolutionary War. It was the longest recorded siege in the annals of the British army.