The 'Siege of La Rochelle' involved Allied and German forces for the French western port city of La Rochelle (12 September 1944/8 May 1945).
La Rochelle was an important German naval base on the Atlantic coast of western France, and had been used for surface ships and U-boats. After the Allied invasions of Normandy and southern France, during the subsequent campaigns that drove the Germans eastward across France and back toward Germany, La Rochelle and other ports, such as Lorient, Royan and St Nazaire, became 'Atlantic pockets' still occupied by the Germans, which were bypassed by the main thrust of the Allied invasion, as was Dunkirk on the North Sea. La Rochelle was liberated only at the very end of the war, nine months after the 'Liberation of Paris', after the Germany’s total surrender on 8 May 1945. The fortress of La Rochelle, which included the islands of Ré and Oléron, was onr of the three last German-held areas of France to surrender.
The Allied siege of the pocket of La Rochelle lasted from September 1944 to May 1945, and was an investment without any real intent to overwhelm the defenders with heavy aerial and/or artillery bombardment. Thus La Rochelle remained in German hands until the end of the war, as did other Atlantic pockets such as St Nazaire and Lorient. The Allies deemed that it was sufficient just to surround the city and not incur the losses which would result from a frontal attack, as the city would ultimately fall anyway with the end of the war. The Germans had fortified this and the other such ports in order to deny their logistical capacity to the Allies and at the same time to maintain the U-boat threat to Allied shipping in the Atlantic.
In total, 39,500 French civilians were under the authority of Vizeadmiral Ernst Schirlitz, the Kommandierender Admiral Atlantikküste (commanding admiral of the Atlantic coast), from 1 March 1943 until the end of 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 difficulties faced by the civilian population inside the walls of 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 and neighbouring La Pallice.
In effect, La Rochelle was surrounded efficiently enough, and suffered enough from the siege as its harbour facilities were damaged by Allied air attacks, that the Germans were unable to use La Rochelle for the launch of major U-boat attacks on Allied shipping for the duration of the siege. Every week a German aeroplane was able to break through the blockade and supply the garrison, however.
From the spring of 1945, Général de Corps d’Armée René Marie Edgard de Larminat, commanding the French forces in western France and on the Atlantic coast, supervised the initiative to contain and eventually to retake La Rochelle. The USA gave logistical support as well as strategic air support to the effort, whose first objective was the nearby Royan pocket. The city suffered a heavy bombardment by 1,000 bombers, which razed the town and killed 1,500 civilians. La Rochelle escaped this fate only because Royan was at the time considered a higher priority as a result of its commanding position on the Gironde estuary, and the 'Mousquetaire' planned assault on La Rochelle, was cancelled with the capitulation of Germany.
La Rochelle was surrendered to the Allies only on 7 May 1945, with a surrender ceremony following on 8 May at 23.45. The Germans surrendered in Dunkirk on 9 May and St Nazaire on 11 May.