Gibraltar ("The Rock") had been ceded to Britain in the Treaty of Utrecht in 1713, ""for ever, without any exception or impediment whatsoever", but Spain had been trying to renege on the treaty ever since. In 1779, with Britain alone against Spain, France, Holland and revolting American colonists, the opportunity seemed to there for the taking.
Spain laid siege with 13,000 men under Martín Álvarez de Sotomayor, including two battalions each of Royal Guards and Walloon Guards of the Spanish army, whilst the cavalry included French Dragoons. There was also a blockade on the seaward side, based at Algiciras, and another Spanish squadron at Cadiz to block reinforcements.
The British, under Governor General Elliot, had 5,382 troops including a Corsican contingent and a Hanoverian Brigade of three battalions. Fortunately, Elliot turned out to be an inspiring and determined leader. And a conscientious one, he had been laying in stores and preparing defences for some time.
The only landward route to Gibraltar was, and is, across a narrow isthmus. Every effort had been made to cover this with as many cannon as possible. Directly across the causeway was a wall and dry ditch with two bastions, mounting 26 guns. Flanking this, and the causeway itself were the King's, Queen's, and Prince's lines cut out of the rock itself. Above were the Willis batteries, and then further batteries up the Rock until the summit, which was crowned with cannon and mortars. The Mole, projecting out past the harbour, was itself fortified and gave a crossfire onto the causeway. There was so much artillery that 100 British infantry were detailed to help man the cannons. The whole was so formidable that it was called the Mouth of Fire by the Spanish. The seaward side was equally covered with bastions and cannon from sea level to the summit, with barriers of old masts and chains blocking the old and new landing stages. Only the Eastern flank, which is a sheer drop into the sea, was unfortified and left to the famous Gibraltar apes. Last, but not least, a huge cistern had been made to collect rain water, so that at no point in the siege was there a shortage of water.
The Spanish troops constructed huge siege works around Gibraltar, and the blockade started to bite. By the winter Gibraltar, with virtually no room to grow food, was starting to suffer. Scurvy, caused by a shortage of fresh vegetables, was common and ships had to be broken up to get firewood. What saved Gibraltar was the Battle of Cape Vincent in January 1780, A massive British convoy under Admiral Rodney not only smashed through the Spanish blocking force at Cadiz, but captured or destroyed 4 ships of the line, including the Spanish flagship. This, the supplies landed, and reinforcement with the 73rd Highlanders gave a huge boost to the garrison morale. The presence of Prince William, son of the King, in the fleet also showed commitment from Britain, and that the garrison was not forgotten.
The Battle of Cape St. Vincent
Running the Blockade
By the summer of 1780 food was running low again, but blockade runners kept them going. Every effort was made to bring in fresh fruit from Africa to hold off scurvy.
Admiralty-Office, September. 18, 1781.
Extract of a Letter from Captain Curtis dated Brilliant, Gibraltar, August 7.
I beg Leave to acquaint My Lords Commissioners that His Majesty's Sloop Helena arrived here this Morning. Her Approach was discovered by the Enemy and us at the same Time, about Five o'Clock. She was in the Gut to the Southward of Cabarita Point, and nearly a Third of the Way over from it towards Europa. It was perfectly calm, and the Helena was rowing for the Rock.
I immediately took the Repulse and Vanguard Gun-Boats, with all the Boats of the Ships; and went for her, as expeditiously as possible. Fourteen Gun-Boats of the Enemy, carrying each One Twenty-six Pounder in the Bow,, moved also from Algaziras, accompanied by several Launcbes. These Boats got on faster than I could proceed with the Repulse and Vanguard, and before Eight o'Clock those of them the most advanced commenced their Fire upon the Helena, being then within Half Gun-shot. She returned it with great Deliberation and Effect, but still continuing to use her Oars. The greater Part of the Gun-Boats were soon close to her, and the Clouds of Grape and other Shot, that seemed almost to bury her were really astonishing. However she could not, without our Aid, bear long this very unequal Combat. The Repulse and Vanguard began a well-directed Fire upon the Enemy, being so placed as was deemed the most efficacious to cover the Helena, and annoy them.
The commencement of the Sea Breeze having got to the Helena she soon reached us, the Enemy still persevering on their attempt upon her, firing at her broadside and others keeping astern, raking her. However the Steadiness and Bravery exhibited onboad the Helena, and the well appointed Grape from the Repluse and Vanguard, very soon made some of them retire, and they had all fled by ten o Clock, allowing us to tow the Helena into the Mole without further molestation. A Xebec, mounting between twenty and thirty guns, which was lying near to Cabarita Point, got under way when the Breeze came and advanced to join the Gun Boats, but upon seeing them retire she retired also.
The Masts, Sails, Rigging and Furniture of the Helena are cut all to Pieces, and the Hull a good deal damaged, but it is as wonderful as it is fortunate that the Boatswain was the only man who was killed on board her. The Bravery, the Coolness, and the Judicious Conduct of Captain Roberts do him infinite Honour and His Officers and Men deserve the highest Commendation.
On 7th June the Spanish sent a fire ship into the harbour. This nearly worked, but the garrison was alerted and at 1am woke to see Gibraltar blood red against the dark night. Cannonades drove off the Spanish boats, and English boats rowed out, hooked the burning vessel, and towed it away. Even then the danger was not over, two more fireships were approaching and almost reaching the pier, but they were fended off just in time. The hulks were later salvaged by the British and used, ironically, as firewood
Yet again food started to run out, especially as supplies from North Africa had been cut, but another convoy arrived in April 1781, and this convoy evacuated all civilians from the Rock.
The Sortie and the Grand Bombardment
It was now clear to the Spanish and French that the British could not be starved out. So in November they assembled ready to storm the defences. the British response took them entirely by surprise. The night before the assault was due fully half the garrison silently left Gibraltar and then flung themselves on the siege lines. It was a dramatic success, batteries were set on fire, cannon spiked and troops routed. Over two million pounds worth of Spanish stores and equipment, an immense sum for the time, was destroyed. the assault had to be cancelled.
Watching the destruction of the Spanish floating batteries from The Rock
But still the Spanish and French persisted. Eventually, on 13 September 1782, nearly three years after the siege started, they started their assault. The plan was to smash Gibraltar´s defences "into powder" and then storm it with 35,000 Spanish and French troops. A fleet of 18 ships of the line, 40 gunboats and 20 bomb vessels surrounded the Rock, as well ten "floating batteries" with 138 heavy guns. These were immense, with guns only on one side, counterbalanced with lead. The cannon side had extra protection, and a roof was made of planks and iron sheets. They were, in a way, the first Ironclads. On the landward side there were 86 more guns. Over 80,000 spectators gathered to watch the show - they were disappointed. The British batteries, with higher elevation, and therefore range, fired red hot shot at the wooden floating batteries, exploding three and damaging the rest. They also damaged the ships so much that they caused 719 casualties. Demoralised, the allies withdrew.
This was the last major assault. In October another large British convoy appeared, 31 transports with supplies and the 25th, 59th and 79th regiments. The siege continued but in February 1783 a peace treaty was signed. Although the British bargaining position was weak the Spanish didn´t press for Gibraltar, gaining instead Minorca and territory in the Americas. Presumably they assumed Gibraltar could be picked off at a later date. It wasn´t.