What was the Great Siege of Gibraltar?

Short answer

The Great Siege (1779 to 1783) was a French and Spanish attempt to recapture Gibraltar. About 7,000 British defenders under Governor General George Augustus Eliott held out against some 40,000 troops for three years and seven months, the longest siege in British military history.

Detailed answer

France and Spain had allied with the American colonies against Britain, and hostilities at Gibraltar began on Thursday 24 June 1779. The besieging forces were commanded by the Duc de Crillon, with General Eliott leading the defence.

The garrison developed the use of red-hot shot, heating cannonballs in furnaces before firing them. On Sunday 8 September 1782 a test against a battery on the isthmus destroyed eight guns in two hours.

The decisive moment came with the Grand Attack on Friday 13 September 1782. Ten floating batteries carrying 138 heavy guns, devised by Colonel D'Arçon, were supported by ships of the line, gunboats, bomb vessels and around 35,000 troops on land. British shot at first failed to penetrate the batteries' thick hulls, but by midnight red-hot shot lodged in the timbers had set them alight. British gunboats rescued 357 sailors from the burning vessels. Franco-Spanish losses were 1,473, against 15 British killed and 68 wounded.

The siege also produced Gibraltar's tunnels. Sergeant Major Henry Ince proposed tunnelling to bring guns to bear on the north face, and work began on Saturday 25 May 1782. By February 1783 the first gallery, Windsor Gallery, was 370 feet long and held four guns.

A truce was signed on Sunday 2 February 1783 and Britain kept Gibraltar. British losses were 333 killed by enemy action and 536 dead from sickness.

Visitors can see the siege's legacy in the Great Siege Tunnels in the Nature Reserve, which include Windsor Gallery and an original 18th-century cannon, at King's Bastion on the town's western defences, and at Ince's Farm on the Upper Rock, still named after Henry Ince.