This was the Free French seizure of the island of Corsica (11 September/4 October 1943).
On 8 November 1942 Allied forces landed in French North-West Africa in 'Torch', and this triggered the German implementation on 11 November of their 'Anton' contingency plan, which included the Italian 'Operazione C2' to occupy Corsica, part of Vichy France', as well as parts of south-east mainland France as far to the west as the Rhone river. The Italian occupation of Corsica had alrady been strongly promoted by the Italian Fascist régime as an element of its irredentist aims.
Generale di Divisione Ettore Cotronei’s 20a Division fanteries 'Friuli' of the VII Corpo d’Armata made an unopposed landing on Corsica: the Gruppo da sbarco (landing group), which had initially been created for the planned invasion of Malta, was available in Italy and disembarked at Bastia in the north-east on the night of 11/12 November; other forces landed at Ajaccio and Porto Vecchio. The absence of Corsican resistance and a desire to avoid problems with the Vichy French then limited the Italian recruitment of Corsicans, except for a labour battalion in March 1943. The Corsican population initially showed some support for the Italians, partly as a consequence of irredentist propaganda. The VII Corps' garrison eventually comprised the 20a Division fanteria 'Friuli, Generale di Brigata Clemente Primieri’s 44a Divisione fanteria 'Cremona', Generale di Brigata’s 225a Divisione di fanteria costiera, Generale di Brigata Attilio Lazzerini’s 226a Divisione di fanteria costiera, one battalion of Alpini and one armoured battalion. The Italian occupation forces were commanded by Generale di Corpo d’Armata Umberto Mondino until 30 November 1942, then Generale di Corpo d’Armata Giacomo Carboni until 18 March 1943 and finally Generale di Divisione Giovanni Magli until September 1943. The initial occupation force numbered 30,000 Italian troops and rose eventually to a figure of almost 85,000 men.
Coastal defence was the task of the 16 battalions of the two coastal divisions. The north of the island was garrisoned by the 20a Divisione di fanteria 'Friuli', the Gruppo da sbarco and Console Giovan Battista Cagnoni’s Blackshirt battalion; the south-west by by the 44a Divisione di fanteria 'Cremona' and Generale di Brigata Gian Carlo Ticchioni’s Raggruppamento 'Sud'; and the centre by Colonello Fucci’s 10o Ragruppamento 'Celere' and Colonello Castagna’s 175o Reggimento Alpini.
Ammiraglio di Divisione Gaetano Catalano Gonzage di Cirella’s Italian naval forces operated from Bastia, Portovecchio and Ajaccio, while Colonello Baudoin’s Italian air forces had bases at Borgo, Ghisonaccia, Ajaccio, Portovecchio and Campo dell’Oro, which were all airfields in the island’s eastern lowlands.
In Corsica, the local collaborationists linked to irredentism supported the Italian occupation, stressing that this was a precautionary measure against an Anglo-American attack. Some Corsican military officers collaborated with the Italians for irredentist reasons and a famous Corsican writer, Petru Giovacchini, who was considered as a governor of Corsica once the island had been annexed to Italy, was associated with this group. During the first months of 1943 these irredentists undertook a major propaganda effort among the Corsican population to promote the unification of Corsica and Italy as a 'Governorate of Corsica' as had been done in 1941 with Dalmatia. There was only lukewarm support for the Italian occupation by the majority of the Corsican population, however, at least into the summer and autumn of 1943 and the Allied invasions of Sicily and the Italian mainland.
After the Italian occupation, Corsica’s social and economic life was left in the hands of the original French civil authorities, in the form of the préfet and four sous-préfets in Ajaccio, Bastia, Sartene and Corte. This was an arrangement which helped to maintain calm on the island during the first months of Italian occupation. On 14 November 1943, the préfet restated French sovereignty over the island and stated that the Italian troops had been occupiers.
The French resistance was initially limited in size and scope, but began to become larger and more organised after the Italian occupation. This was initially centred on two movements. One was a network operating under the codename 'Mission Secrète Pearl Harbor', which arrived from Algiers on 14 December 1942 on board the Free French submarine Casabianca. The mission was headed by Roger de Saule, and co-ordinated various groups that merged in the Front National. Communists were very influential in this movement. The other network was the R2 Corse organisation which had originally been established during January 1943 in connection with the London-based Free French movement headed by Général de Brigade Charles de Gaulle. Its leader, Fred Scamaroni, failed to unite the movements and was subsequently captured and tortured, and then committed suicide on 19 March 1943.
In April 1943 Paulin Colonna d’Istria was despatched from Algeria by de Gaulle with the task of uniting the two movements. By a time early in 1943, the resistance was sufficiently organised to request arms deliveries. The resistance leadership was strengthened, and the movement’s morale was boosted by six visits by Casabianca carrying personnel and arms. Allied air drops later delivered more weapons. This made it possible for the resistance to increase its activities and establish greater territorial control, especially over the countryside by the summer of 1943. In June and July 1943 the Organizzazione per la Vigilanza e la Repressione dell’Antifascismo (OVRA, the Italian fascist secret police) and the Black Shirt paramilitary groups began mass repression, 860 Corsicans being jailed or deported to Italy.
It had been decided at the 'Quadrant' first conference at Quebec between 17 and 24 August 1943 that the islands of Sardinia and Corsica, parts of Italy and France respectively, should be recaptured only after Italy had left the war and the Allies had established air bases, in the area of Rome, from which air support could be provided for these undertakings. The Allied schedule was now overtaken by German decisions, however, for the Germans had created their 'Achse' (ii) plan to forestall an Italian surrender and defection to the Allies. This plan was launched on 8 September, and included the evacuation of the garrisons of Sardinia to Corsica. When news of the Armistice of Cassibile on 3 September was announced on 8 September, the Germans began to embark their forces at the ports of La Maddalena and Santa Teresa Gallura on the northern coast of Sardinia, landing at Porto-Vecchio and Bonifacio in Corsica without opposition from the nearby Italian coastal artillery batteries. The Germans used craft available since the evacuation of Sicily and such barges that could be diverted from transporting fuel from Livorno to the front in Italy to transport their troops from Sardinia to Corsica. The Fliegerführer 'Sardinien' moved to Ghisonaccia airfield in Corsica on 10 September, becoming the Fliegerführer 'Corsica', and on the next day the last 44 Luftwaffe aircraft in Sardinia arrived.
At 00.00 on 8/9 September, German naval infantry captured Bastia harbour, damaged the torpedo boat Ardito and killed 70 of her crew. The 7,980-ton merchant ship Humanitas and a motor torpedo boat were also damaged, but the torpedo boat Aliseo managed to sail at the last moment. On the next day, Italian troops counterattacked and forced the Germans out of Bastia and the port commander ordered Capitano di Corvetta Fecia di Cossato, the captain of Aliseo, to prevent German ships in the harbour from escaping. At dawn on 9 September, 'Aliseo's lookouts sighted German ships leaving the harbour in the early-morning mist and turning to the north close to the coast.
Aliseo was both outnumbered and outgunned, her only advantage over the Germans vessels being her speed, but she nonetheless closed on the submarine chaser UJ 2203 as the latter opened fire, zigzagging but closing to a range of about 7,980 yards (7300 m), unil at 07.06 she began to fire at the German ships. At 07.30 Aliseo was hit in the engine room and brought to a stop, but the damage was quickly repaired. Aliseo caught up with the German vessels and closed the range, hitting UJ 2203 and some of the barges. At 08.20 UJ 2203 exploded with the loss of nine of her crew. Aliseo then fired on UJ 2219, which exploded and sank 10 minutes later. The barges, which were well-armed and had been firing continuously, separated but three of them had been sunk by 08.35. Five minutes after this, Aliseo attacked two other barges, under fire from Italian shore batteries and the corvette Cormorano, which were beached. Aliseo rescued 25 Germans, but 160 other Germans had been killed.
Between 8 and 15 September, the Germans undertook demolitions on seven Sardinian airfields, but Italian aircraft had begun landing on other airfields on 10 September, some en route to Sicily and Tunisia to join the Allies but others to operate from Sardinia with the Allies. Five Cant Z.1007 bombers attacked German ships in the Bay of Bonifacio on 16 September, and Luftwaffe aircraft retaliated with attacks on operational Sardinian airfields for the next four days. By 19 September, the 90th Panzergrenadierdivision, a fortress brigade, anti-aircraft batteries and Luftwaffe units totalling 25,800 men, 4,650 vehicles and 4,765 tons of supplies had departed Sardinia for Corsica, on which a large part of Generale di Brigata Ercole Ronco’s 184a Divisione paracadutisti 'Nembo' had defected to the Germans.
Corsica was now to be held by the combined strength of SS-Brigadeführer und Generalmajor der Waffen-SS Karl Herrmann’s (from 18 September SS-Standartenführer Herbert von Obwurzer’s) Sturmbrigade 'Reichsführer-SS' and one battalion of Generalmajor Ernst Günther Baade’s 15th Panzergrenadierdivision (already in Corsica) plus Generalleutnant Carl Hans Lungershausen’s 90th Panzergrenadierdivision, three battalions of Oberst Almers’s Festungsbrigade 'Almers', and support units (evacuated from Sardinia between 8 and 19 September), under the overall command of Generalleutnant Fridolin Ritter und Edler von Senger und Etterlin from 7 September. The German commander received assurances from Magli that the Italian garrison would continue to fight against the local resistance and not oppose the arrival of German troops from Sardinia. There were about 20,000 French resistance fighters on the island at this time, and the Germans suspected that many of the Italians would defect to them.
On Corsica were some 20,000 French resistance fighters and the occupation forces of Magli’s VII Corps, which suffered a heavy rate of desertion to the resistance in the centre of the island. While their leaders were ambivalent, most of the Italian troops remained loyal to the Italian king, and some fought (mainly at Teghime, Bastia and Casamozza) alongside the resistance forces against the Germans until the liberation of Corsica. The resistance forces aimed to establish control of the mountains in the centre of the island so that the occupation forces could not move overland from one coast to the other, and so facilitate an Allied invasion.
The liberation of Corsica began with an uprising ordered by the resistance on 9 September. The Allies did not initially want such a development, for they preferred to focus their effort on the 'Avalanche' invasion of Italy.
Général d’Armée Henri Honoré Giraud, commanding the French forces in the Mediterranean, was worried that the resistance would be overwhelmed by this German strength. However, in light of the insurrection which had already started, the Allies acquiesced to the landing of elements of the French I Corps d’Armée, raised from 16 August in Algeria under the command of Général de Corps d’Armée Henry Jules Jean Martin, on Corsica in September 1943, the only provision being that the French would have to find their own transport vessels as all Allied capacity was currently involved in 'Avalanche'.
After a small initial force had been landed from Casabianca at Arone near the village of Piano in the north-western part of Corsica, 'Vésuve' thus used two French cruisers, two destroyers and one submarine to ferry some 6,400 troops of the I Corps d’Armée (Général de Division Charles Paul Augustin Louchet’s 4ème Division Marocaine de Montagne, 1er Régiment de Tirailleurs Marocains, 4ème Régiment de Spahis Marocains, 2ème Groupe de Tabors Marocains, one battalion of the Commandos de Choc, and the 3/69ème Régiment d’Artillerie de Montagne) to Ajaccio on the western side of the island between 13 and 27 September.
von Senger und Etterlin had hoped to receive the German reinforcements with which he would be able to hold the island, and after the Italian armistice with the Allies on 9 September the Germans began to disarm the units of the Italian garrison. At this juncture Magli ordered the Italian forces to consider the Germans rather than the Allies as Italy’s enemy, and after this Italian units on Corsica co-operated with the French forces. However, taking the 20th Divisione by surprise in the north-eastern port of Bastia on the night of 13 September, the SS troops seized 2,000 Italian prisoners and secured the port from which the Germans could evacuate their forces as ordered by Hitler on 12 September.
The evacuation was controlled with meticulous precision by Fregattenkapitän Gustav von Liebenstein and Oberst Hubertus Hitschold, the Fliegerführer 2 (ex-Fliegerführer 'Sardinien'), and by 3 October the operation had removed all personnel (27,347 Germans, some Italians and about 1,200 prisoners of war) and considerable stores from the island despite the increasing strength of French resistance attacks with military support. Despite British naval support, the French were unable to land forces quickly enough on Corsica to prevent the bulk of the German troops from reaching their exit ports on the eastern coast of the island. The final fighting took place around Bastia, with the island secured by French forces by 4 October, by which time the Germans had suffered 700 casualties and lost 350 men taken prisoner. The Italians had lost 800 men, and the French had 75 killed, 12 missing, and 239 wounded.
From October 1943 to May 1944, the I Corps d’Armée organised the defence of Corsica, undertook training, and moved units between Corsica and North Africa. On 18 April 1944 the I Corps d’Armée was subordinated to Général d’Armée Jean Joseph Marie Gabriel de Lattre de Tassigny’s Armée B, soon redesignated as the 1ère Armée.
Subsequently, the US forces established 17 airfields, nicknamed 'USS Corsica' as bases for attacks mainly on targets in German-occupied Italy.