Invasion of Minorca ( 1781 ) The Franco - Spanish conquest of Minorca from its British defenders in February 1782 , after the Siege of Fort St . Philip lasting over five months , was an important step in the achievement of Spain ' s aims in its alliance with France against Britain during the American War of Independence . The ultimate result was the ceding of the island to Spain in the Treaty of Paris in 1783 . Background . At the eastern end of the island of Minorca is the port of Mahón , one of the best deep - water anchorages in the Mediterranean Sea . For a naval power with no Mediterranean coast , possession of Minorca , therefore , was of major strategic advantage , and for most of the 18th century , Minorca was in the hands of the British . The narrow entrance to the port was guarded by a fort , known to the British as St . Philip ' s Castle , a translation of the original Spanish , " el castillo de San Felipe " , which ( with two outlying fortlets , San Carlos and Marlborough ) was massively strengthened after the unfortunate events of 1756 , when Admiral John Byng judged the safety of his fleet more important than the possession of the fort , and was subsequently shot to encourage other admirals to take a more positive view of their duties . Although the French won that battle , they lost the Seven Years ' War in 1763 , and so Minorca was returned to Britain rather than France ' s ally Spain , to which the island was historically tied . The Spanish government renewed its alliance with France against Britain by means of the Treaty of Aranjuez ( 12 April 1779 ) , with the recapture of Minorca as one of its main aims . Although secondary to the recapture of Gibraltar , Britain ' s other Mediterranean sea - fortress , removing Minorca from British control was important because it was home to a thriving fleet of privateers , licensed by the Governor , Lieutenant - General James Murray , to seize vessels which might be doing business with Britain ' s enemies . Plans for reconquest . The plan to recapture Gibraltar in 1779 did not go well , and by the end of 1780 , Spain ' s military leaders were accepting that they would have to embark on some of their other projects in parallel with the long siege there . An invasion of Minorca was therefore planned during the first few months of 1781 , largely by Don Luis Berton de los Blats , Duque de Crillon ( or rather , Duc de Crillon , for he was actually French , a descendant of " the man without fear " , Louis des Balbes de Berton de Crillon ) . In theory , he was working with Spain ' s War Ministers , and Foreign Minister José Moñino y Redondo , conde de Floridablanca ; in practice , the relationship between the two men seems to have been somewhat strained , and de Crillon perhaps did not take as much advice as he should have . The invasion fleet . On 25 June 1781 , a French force of about 20 warships , commanded by Admiral Guichen , left Brest on a coastal patrol , which happened to involve sailing into the Mediterranean . They were going to provide additional protection for the invasion fleet , but , in order to fool the British , they would not be joining their Spanish allies until they were close to the target . The Spanish invasion fleet ( 51 troop carriers , 18 supply vessels , 3 hospital ships , 3 " viveres " , 2 bombardment ships , a fireship , and 13 armed escorts ) , departed Cadiz on 23 July 1781 , initially heading westward to appear as if its destination was America , but turned in the night and passed Gibraltar on 25 July . Facing contrary winds in the Mediterranean , by 29 July the convoy was beginning to break up , and was forced to take shelter at La Subida cove , near Cartagena . At some time over the next few days the Spanish were discreetly joined by the French warships . The combined fleet left La Subida on 5 August , came within sight of Alicante on 14 August , then in the night of 17 August headed away from the Spanish coast and sailed parallel to Formentera . On 18 August , as it passed the little island of Cabrera , south of Majorca , the fleet was joined by another 4 warships , from Palma . That night , the wind blew from the south - east , and the fleet had to take precautions to avoid being blown aground on Majorca , but Minorca was sighted the next morning . The invasion plan . A main force was to be landed at Mesquida bay , just north of the main target , Port Mahón , and a secondary force at Alcaufar bay , south of the port , while the other two significant harbours on the island , at Ciudadela and Fornells , were to be blockaded . The Mesquida force was to move rapidly to the town of Mahón , where the Governor lived , to capture him and as many British soldiers as possible . The Alcaufar force was to block the road that led from the British residential suburb , Georgetown ( now Es Castell ) , to the fort of St . Philip ' s Castle . At about the same time , a third force was to land on Degollador beach at Ciudadela , to block the main road across the island . Finally , a detachment would be landed at Fornells , to take the small artillery fort there . The invasion reality . This plan had one basic flaw – the assumption that the British would believe a vast convoy approaching Minorca had friendly intentions . Additionally , further modifications had to be made because of the wind , which forced the main part of the fleet to sail round the south of the island , rather than the north ; the landing at Ciudadela was also temporarily impossible . So , about 10 : 30 am , the fleet rounded Aire island , at the south - east tip of Minorca , and began the approach to Port Mahón , while the Alcaufar contingent headed for land . A little after 11 : 30 , the leading vessel of the fleet , " San Pascual " passed St . Philip ' s Castle , its crew at battle stations ( immediate battle was not anticipated , but this was a naval tradition ) . Finally , around 1 : 00 pm , " San Pascual " arrived at Mesquida , and the rest of the fleet gradually caught up , and preparations for landing began . At 6 : 00 pm , the Spanish flag was raised on the beach , and received a 23 - gun salute . The British had a watchtower on the south coast of Minorca , and had spotted the fleet approaching . An urgent message was immediately sent to Mahón ; later reinforced by a more detailed report from the watchtower on Monte Toro , in the centre of the island . By midday , most of the British personnel around Mahón had been moved within the walls of St . Philip ' s Castle , a chain had been fixed across the entrance to the port , and small vessels were being sunk in the narrow channel , making entry by sea impossible . Some dependants , including the Governor ' s family , made preparations to sail to safety in Italy aboard a Venetian ship , and a message about the invasion was sent to the British envoy at Florence , ending with an assurance that the garrison was in " high health and Spirits " and would make " a vigorous resistance " ( the ship reached Leghorn – Livorno in Italian – on August 31 ) . When the Spanish troops entered the town of Mahón , most of the remaining population was on their side , and greeted them with cheers . At Georgetown only 152 prisoners were taken , and the troops sent to Ciudadela and Fornells on 20 August found only token British forces of about 50 men . While arrangements were made to put the island under a Spanish administration , letters were exchanged between de Crillon and Governor Murray , and the invaders began preparing their own defences against counter - attacks . By 23 August there were over 7 , 000 Spanish soldiers on Minorca , and 3 , 000 more soon joined them . The bulk of the fleet left once the troops were securely established , and Guichen arrived back at Brest on 15 September . When news of the invasion got back to Britain about four weeks later , newspapers reported that the garrison consisted of some 5 , 660 men . However , of that number , 1 , 500 were members of the local militia , and 400 were civilian workers . Very few members of those groups actually went into the fort , except for a few members of the international business community the British had welcomed onto Minorca – north African , Jewish , Greek etc . ( incidentally , the remainder of the African and Jewish communities were expelled by the invaders on September 11 , and various other foreign nationals shortly afterwards ) . Also , the number of soldiers included those captured elsewhere on the island by the invaders , so the real total of fighting men in the fort would be closer to 3 , 000 – and it seems that even that was an exaggeration to discourage the invaders . The siege begins . Work soon began on gun emplacements to besiege St . Philip ' s Castle , the most important being at La Mola , on the opposite side of the harbour mouth , and at Binisaida , near Georgetown . The British did not make this easy ; they directed their own guns at the work sites , and also occasionally sent troops out of the fort . The most notable of these sallies took place on 11 October , when between 400 and ( as the Spanish newspapers had it ) 700 soldiers crossed the harbour to La Mola , and captured eighty soldiers with eight officers . Spanish troops were sent in pursuit , but too late ; the officers were later freed after giving their word of honour that they would not enter combat again unless exchanged for captured British officers . Three British soldiers were killed in the action . Although this action was a success for the British , relations between Murray and his deputy , Lieutenant General Sir William Draper , were becoming strained by this time , due to arguments over their respective areas of authority and would later deteriorate much further . Even before this , there was considerable discontent among de Crillon ' s troops , comparisons being made with the futile Spanish attack on the city of Argel ( Algiers ) in 1775 . Reinforcements had therefore been ordered , and by coincidence , the first boatload arrived at Fornells from Marseilles the day after the British attack . By 23 October two brigades ( one French and one German ) totalling 3 , 886 men had been added to the 10 , 411 already on the island . Also at this time , de Crillon was requested by the Spanish government to attempt an alternative strategy . Among the rather confused reports which filtered through to Britain from Minorca , delayed by several months , were two letters published in the London papers at the end of January 1782 . One is from Murray to de Crillon , dated 16 October 1781 , sharply reminding him that the Murray family tree is as noble as the Duc ' s , and that when a former Duc de Crillon was asked by his King to betray his honour , he refused . The other is de Crillon ' s reply , indicating that he personally is happy to accept Murray ' s criticism . The source of this exchange was an offer to the governor of 500 , 000 pesos ( then worth just over £100 , 000 – but inflated in some sources to £1 , 000 , 000 ) plus a guaranteed rank in the Spanish or French army , in return for surrender . The great bombardment . On 11 November the besiegers ' mortar batteries began operation . In the first couple of days the only item damaged within the Castle was the carriage of a small 6 - pound gun . One mortar battery was destroyed when a shell fired from the Castle blew up its powder magazine . The Castle gunners also succeeded in sinking a supply vessel attempting to unload at the Georgetown quay . This information was reported in two letters from General Murray , dated 12 and 13 November , which somehow got back to England by 4 December . Letters were also being sent from the British government to Murray , praising the bravery of the garrison and promising help as soon as possible . In practice , with Gibraltar also under siege , the British were relying on the elaborate improvements which had been made at St . Philip ' s Castle after the 1756 embarrassment – which included the provision of food for over a year . After nearly two months spent weakening the fort with artillery , 6 January 1782 was the date set for the beginning of a final assault . In the first days of this attack , intensified bombardments from 100 cannons and 35 mortars did such damage to the outer defences that Murray had to pull all his troops back within the inner citadel . However , when firing slackened the defenders would begin their own bombardments of the attackers ' positions , with over 200 cannons and 40 mortars – they also sank another supply vessel on 12 January . Three days later the attackers got their revenge , setting fire with a well - aimed incendiary grenade to a key storehouse , containing , among other things , much of the fort ' s supply of salted meat , which burned for four days . About this time , also , the relationship between Governor Murray and Lieutenant - Governor Draper broke down completely , and after an unpleasant incident the latter was suspended from duty . The British defeat . To the garrison , the loss of meat was a relatively minor problem . The improvements at the fort had not included artillery - resistant vegetable gardens , so the occupants had no access to fresh vegetables , the most reliable medicine to combat the disease scurvy , now known to be caused by vitamin deficiency . Gradually , more and more of the soldiers showed serious symptoms , and at the beginning of February the number in hospital was growing by more than 50 per day . To keep watch at all points of the complex defences , 415 men were required . With only 660 men able to perform any duties at all by 3 February , the garrison was therefore 170 men short of the 830 necessary to maintain two shifts of guards in a day . Of those 660 men , 560 showed symptoms of scurvy , and several men died while on sentry duty , having chosen not to report their condition to the medical officers . Following a series of urgent reports by his medical team , on 4 February 1782 General Murray sent a list of ten surrender terms to the Duc de Crillon , based on the principle that the garrison should be provided with transport back to Britain , which would be paid for by the British government . These had to be rejected , as de Crillon had been instructed to insist on the garrison being declared prisoners of war , but he hinted strongly that a compromise should be possible . The final agreement , accepted by both sides on 5 February and signed on 6 February , allowed the men to become temporary prisoners of war while they waited for the transport ships , and even stipulated that " in Consideration of the Constancy and Valour which General Murray and his Men have shewn in their brave Defence , they shall be permitted to go out with their Arms shouldered , Drums beating , lighted Matches , and Colours flying , till having marched through the Midst of the Army , they shall lay down their Arms and Colours " . This the 950 or so who could walk duly did , the ranks of Spanish and French troops stretching all the way along both sides of the road from St . Philip ' s Castle to Georgetown , where the defenders laid down their arms in surrender " to God alone " . Though he looked straight ahead as he marched , Murray was informed by de Crillon and his deputy the Baron de Falkenhayn that many of the French and Spanish wept at what they saw . In some respects , De Crillon and his subordinates went far beyond the agreement , and Murray noted that they provided " every Thing which can contribute to our Recovery " . Aftermath . The " Gaceta de Madrid " estimates of Spanish casualties ( 22 February 1782 ) were 184 killed and 380 wounded . According to the " London Gazette " report of the end of the siege , 59 of the British garrison were killed . This left 2481 military personnel , including 149 wounded , to surrender , suggesting either that a large number of deaths from scurvy were ignored , or that the earlier British claims about the size of the garrison were significantly exaggerated . Also emerging from the fort after the surrender were 43 civilian workers , 154 wives , and 212 children . The castle itself , after some discussion among Spanish military planners , was later damaged beyond easy repair , so that it could not be seized in the sort of surprise attack de Crillon had intended , and used against the Spanish . Following his success , the Duc de Crillon was awarded the title " duque de Mahón " and put in charge of the attempt to recapture Gibraltar , where he embarked upon a bold plan to storm the citadel – for the result , see Great Siege of Gibraltar . Lieutenant General James Murray was court - martialled in November 1782 , on charges brought by Sir William Draper . Murray was found guilty of only two offences ( the more serious of which was the issuing of an order derogatory to his deputy – the spark which had led to Draper ' s suspension in January ) . In January 1783 he was sentenced to a reprimand , and shortly afterwards , by the direct intervention of King George III , he received an apology from Draper for certain words spoken out of court , which might otherwise have led to a duel . In February he was promoted to full General , but having passed his 60th birthday during the siege , he never returned to active service , though he became colonel of the 21st Fusiliers in 1789 . Britain captured Minorca again in 1798 during the French Revolutionary Wars , but returned it permanently to Spain in 1802 following the Treaty of Amiens . Principal source . Terrón Ponce , José L . " La reconquista de Menorca por el duque de Crillon ( 1781 – 1782 ) " Mahón , Museo Militar ( 1981 ) – accessed 2007 - 12 - 17