Allied siege of La Rochelle The Allied siege of La Rochelle occurred during the Second World War in 1944 – 45 , when Allied troops invaded France . La Rochelle was an important German base on the Atlantic , especially a major submarine base from where U - Boat campaigns were launched . Until the end of the war , La Rochelle was , with other harbours such as Royan or Saint - Nazaire , one of the remaining " Atlantic pockets " occupied by the Germans , which had been bypassed by the main thrust of the Allied invasion . On the North Sea , Dunkirk was similarly bypassed . The city was only liberated at the very end of the war , nine months after the Liberation of Paris , after the general German capitulation on 8 May 1945 . The siege ( September 1944 – May 1945 ) . The " pocket " of La Rochelle ( " Poche de La Rochelle " ) was a zone extending to a distance of about 10 kilometers around La Rochelle , reinforced by an anti - tank trench . After the allied landing in Normandy in June 1944 , a large number of German troops had regrouped in the area . The allied siege of the pocket of La Rochelle lasted from September 1944 to May 1945 , without heavy bombardment . La Rochelle remained in German hands until the end of the war , much as other Atlantic harbours such as Brest , Saint - Nazaire , Lorient , Gironde - Nord , Gironde - Sud because the main thrust of the war was more concerned with focusing on Germany itself . Just surrounding the city was considered wiser than leading a frontal attack , as the city would ultimately fall anyway with the end of the war . The German command also wished to keep control of the coastal garrisons and rejected evacuation in order to maintain a threat on Allied shipping in the Atlantic . In total 39 , 500 French civilians were under the rule of Vice - Admiral Schirlitz , head of Navy Command West , in La Rochelle during the war . The German garrison numbered 22 , 000 men . During the siege the Allies still allowed for electricity , wood and some supplies to be delivered in order to alleviate the ordeal of the civilian population inside the walls of the city . The Free French Forces were opposed to such a passive attitude , and desired to take these coastal cities by force , mostly out of considerations of national pride . FFI troops , however , remained unable to capture the city . Agreements were made between the French and the German occupation force in La Rochelle , to the effect that the French would not attack and that in exchange the Germans would not destroy the port installations of La Rochelle - La Pallice . In effect , La Rochelle was surrounded efficiently enough , and suffered enough from the siege , with harbour facilities being damaged by Allied air attacks , that the Germans were unable to launch major U - Boat attacks on Allied shipping for the duration of the siege . However , every week a Luftwaffe plane was able to break through the blockade and supply the garrison . In order to raise the morale of German troops in La Rochelle , the propaganda movie " Kolberg " , celebrating resistance against the French in 1806 , was sent in by Göring and premiered simultaneously in Berlin and La Rochelle on 30 January 1945 . Allied offensive against German " Atlantic pockets " . From spring 1945 , General De Larminat was put in charge of French forces in the region , with the objective of capturing La Rochelle . The United States was to give logistical support as well as strategic air support . Operation " Vénérable " . The first city to be attacked was the nearby city of Royan , held by 5 , 500 German troops and inhabited by 3 , 000 French civilians . The city suffered a first strategic bombing on 5 January 1945 by the RAF , and then a massive attack by Allied troops under the French General de Larminat in Operation " Vénérable " on 14 April 1945 , involving USAAF bombings on the 14th and 15th , bombardment by the fleet of Vice - Admiral Joseph Rue , and land attack by the 10th French Division and the 66th US Division . The French command apparently had advocated that the French harbours should be retaken by military force , rather than awaiting their eventual surrender by the Germans . The city suffered heavy bombardment by 1 , 000 planes , including those of the USAAF ' s 447th Bomb Group , with the result that the city was razed , and 1 , 500 civilians killed , in what has been described by the historian Howard Zinn as a " crime " . Altogether , 27 , 000 artillery shells were fired over Royan , and the city saw one of the first military uses of napalm on 15 April 1945 , dropped by Allied bombers , which made the city " a blazing furnace " . Operation " Mousquetaire " . La Rochelle only escaped this fate as Royan was at the time considered as a higher priority , due to its commanding position on the Gironde River . After Royan was taken , Ile d ' Oléron was also captured in Operation " Jupiter " , and de Larminat was planning to capture La Rochelle next in " Opération Mousquetaire " , but the plan was cancelled with the capitulation of Germany . The French regiments which participated to the operations were under - strength units incorporating FFI elements : the 50th and 158th Regiments of the French 23rd Infantry Division ( known as " Division de marche Oléron " ) , in conjunction with the French 2nd Armored Division and other elements . The " 4e régiment de Zouaves " especially participated in the liberation of La Rochelle . La Rochelle was the last French city to be liberated in 1945 . It was only surrendered to the Allies on 7 May 1945 , with the surrender ceremony occurring on 8 May 1945 , at 23 : 45 . Legacy . US troops would remain in the area around La Rochelle , within the dispositions of the Atlantic Alliance , at the bases of La Rochelle , Croix - Chapeau , Bussac - Forêt , and Saint - Jean - d ' Angély ( Fontenet ) until 1966 , when Charles de Gaulle withdrew France from the military wing of NATO , and ordered the closure of NATO bases in France . On 7 September 1996 , a monument was established near the boundary of the La Rochelle pocket , near Saint - Sauveur - d ' Aunis , the " Mémorial de la poche de la Rochelle " , in memory of the soldiers who died in the operation .