Defensive Organization of Corsica The Defensive Organization of Corsica ( " Organization Défensive de la Corse " ) was the French military organization that in 1940 was responsible for the defense of the French island of Corsica against a potential invasion by Fascist Italy . As part of the overall effort to fortify France ' s borders which included the Maginot Line , the fixed Corsican defenses were constructed in parallel with the Maginot Line , using the same organizational structure and similar designs , albeit scaled back in size , cost and fighting power . The Corsican defenses were designed to deter an Italian landing on the south end of Corsica , and to support artillery batteries capable of controlling the Strait of Bonifacio between Corsica and the Italian island of Sardinia , separated by only twelve kilometers . As World War II unfolded , no attempt was made by Italian forces to mount an opposed landing on Corsica . The island was instead occupied after the armistice of 25 June 1940 . In 1943 Corsica saw fighting when German forces moved from Sardinia . Most of the fortified positions remain to the present day . Concept and organization . During the inter - war period , Corsica ' s defenses were first examined in 1926 , when General Debeney requested a study of the island ' s defenses from Vice - Admiral Salaun , the French Navy chief of staff . The island was only twelve kilometers from the Italian island of Sardinia across the Strait of Bonifacio , and was regarded as weakly defended . Salaun ' s report indicated that the island ' s capital , Ajaccio , was relatively well - defended by old 120mm field guns , but that the areas on Bonifacio in the south and Bastia in the north were vulnerable to amphibious assault . Both attack and defense would be hampered by the island ' s poorly developed road network . Bonifacio , the closest point to Sardinia , could control the straits and provide a means of counterattacking Italian territory . In 1928 Bonifacio received five batteries of mounting a total of eight 190mm guns and six 95mm guns , both types of late 19th - century manufacture . At the same time , two 340mm gun turrets were proposed for Bonifacio , similar to those eventually installed at Battery Cepet in Toulon and at Bizerte in Tunisia . The 200 million franc cost of these batteries caused the turret project to be placed in a low - priority status . General Fournier , in charge of Corsican defenses in 1932 , was directed by the Ministry of War on 13 April 1928 to prepare a defensive plan for the island . Fournier prepared an ambitious plan , proposing roads , airfields , telephone communications and other measures , which were projected to cost as much as 6 billion francs . Fournier was told to make do with 42 million francs . Exercises in 1929 showed up the vulnerability of Bonifacio , prompting Fournier to propose a 10 million franc program to defend the southern beaches and the roads near Bonifacio . However , while the French Senate was amendable to funding , none was provided , and the 42 million franc program was cut from the 1930 budget . Bonifacio ' s defenses were augmented in October 1932 with eight 194mm guns in the town ' s citadel , four 138mm guns and four 75mm anti - aircraft guns at Bocca - di - Valle , four 145 / 155 guns at Sotta and six 164mm guns at Monte - Léone . Many of these weapons had sufficient range to fire across the straits . , particularly the guns at Sotta , which had a range of . These open emplacements lacked close - range defenses and were vulnerable to a landing behind the main artillery line . However , from 1931 the " Commission d ' Organisation des Régions Fortifiés " , or CORF , was directed to advise on the defense of Corsica . The same year , a proposal was approved by the Army and Navy to fortify Corsica . The programme included improvements to infrastructure , with new roads and telephone communications , as well as the construction of casemates and " ouvrages " around Bonifacio . Costs were estimated in 1933 at 27 million francs , about half of which was to be spent on fortifications , with the remainder devoted to roads and communications . Construction . Construction of the CORF positions began in 1932 , concentrating on the southern end of Corsica with three objectives : fortification of beaches suitable for the landing of an invasion force , control of the road between Porto - Vecchio and Bonifacio , and defense of the Pertusato plateau behind Bonifacio , site of several of the artillery batteries . A total of twelve infantry casemates and three artillery casemates were completed in 1932 - 1933 . CORF was disestablished at the end of 1935 . As war with Italy and Germany threatened in 1939 , new measures were proposed for Corsican defenses . 5 . 4 million francs were allocated to improve the defenses of Bastia , building two casemates and two blockhouses . In the south , fifteen infantry shelters or " abris " were built in the Corpo - de - Verga area , known as the " Mollard Line , " named after the island ' s military commander . These positions were built by the Military Works Arm ( " Main d ' Oeuvre Militaire " , or MOM ) , which was responsible for many hastily - built fortifications of the immediate pre - war period . Command . Corsica was under the overall command of the General Mollard . Mollard ' s troops included the 363rd Infantry Demi - Brigade ( " 363e Demi - Brigade d ' Infanterie " ) ( 363 DBI ) with four ( later three ) battalions , the 373rd Alpine Infantry Demi - Brigade ( " 373 Demi - Brigade Alpine d ' Infanterie " ) ( 373e DBIA ) with seven battalions , and the 43rd Squadron of the 10th Dragoons Regiment ( cavalry ) ( " 43e Escadron du 10e Régiment de Dragons " ) . Another three or four battalions from various units rounded out the force , supported by the 92nd Artillery Group . Description . All works were built by CORF unless otherwise noted . Northern Corsican Group . Colonel d ' Omano , commander Subsector of Calvi . VIII / 373rd DBIA Sub - sector of Bastia . X / 373rd DBIA , 174 / 405th battery DCA Sub - sector of Golo - Cervione . IX / 373rd DBIA Southern Corsica Group . Lietenant Colonel Ricatte , followed by Colonel Denis from May 1940 . Sub - sector of Porto - Vecchio . A light infantry company Sub - sector of Bonifacio . V / 373rd DBIA , I and III / 363rd DBIA , 150th regional battalion , 3rd and 8th batteries 92nd Artillery Regiment , 175 / 405th battery DCA Sub - sector of Sartène . II / 363rd DBIA Independent sub - sectors . Sub - sector of Aleria . VII / 363rd DBIA , VIII / 373rd DBIA , 171 / 405th battery DCA Sub - sector of Ajaccio . VI / 373rd DBIA , 172nd and 173rd batteries 405th DCA History . Corsica was not directly attacked by ground forces in 1940 . Between 15 June and 20 June the Italian Air Force bombed Propriano , Porto - Vecchio , Bonifacio and Calvi , with little effect . Corsica was occupied by Italian forces after the armistice of June 25 , 1940 , but remained French territory under the Vichy French government . During the fighting of 1943 , in which German forces moved from Sardinia to Corsica and then to Sicily , the Georges - Ville casemate was destroyed and the casemates at Ventilègne and Catarello were damaged . The artillery casemates ' 75mm guns were salvaged after the war and sent to re - arm positions in the Fortified Sector of the Maritime Alps . Present status . The casemates at Rondinara , Santa Manza and other locations are reported to be in good condition and accessible .