The Great Siege ran from 24 June 1779 to 7 February 1783. It was a naval affair even though most of the fighting took place around a fortress. Britain held Gibraltar chiefly because the base served the Royal Navy at the entrance to the Mediterranean. That role became still more important after the loss of Minorca, establishing why the Rock was worth a prolonged defence.
Chapter · 0:22-1:52
The Great Siege begins as a contest over a naval base
The opening dates the three-and-a-half-year siege and explains that Gibraltar's value lay above all in its service to the Royal Navy, especially after Britain lost Minorca.