The Saint-Nazaire Pocket (, ) existed from August 1944 until 11 May 1945 and was formed by the withdrawal of German troops from Loire-Inférieure (now Loire-Atlantique) during the liberation of the department by the allied forces. It was centred around the port and the submarine base of Saint-Nazaire and extended to the east as far as Saint-Omer-de-Blain and from La Roche-Bernard in the north to Pornic in the south. Background After the battle of Normandy and Operation Cobra, the Allies quickly liberated the west of France during the first fortnight of August 1944 (Rennes on 6 August, Nantes on the 12th, Rezé on the 29th). Pockets of resistance however formed as German troops withdrew to the Atlantic coastal ports of Brest, Lorient, Saint-Nazaire, La Rochelle and Royan . The Germans wanted to retain these strategic areas and declared them "fortresses" (). On 31 July 1944, Hitler ordered his Generals Jodl and Warlimont to "defend them to the last man". The hope was that these could once again become significant footholds on the Atlantic in the event that the secret weapons (Wunderwaffe) would be developed in time to turn the war back in the Reich's favour. Also denying the Allies these deep-water ports would hamper operations following the Normandy campaign. The Allies also favoured a mainly eastward advance of the offensive towards Germany. They however left troops to protect the edges of these pockets, assisted by the French army and by battalions of the French Forces of the Interior (FFI) and Francs-Tireurs et Partisans (FTP). The Brest pocket fell on 18 September 1944 after hard fighting, the other four lasted until the surrender of the 8 May 1945, or shortly thereafter. German defences This particular pocket centered on the town and fortified submarine base of Saint-Nazaire but spread out further. North of the Loire, the front line followed the left bank of the Vilaine river, then the Isac (the Nantes-Brest canal), as far as the part of Blain west of the canal; it then descended south-west to Cordemais, passing between Bouvron, Fay-de-Bretagne and Le Temple-de-Bretagne. South of the Loire, it included the municipalities of Frossay, Saint-Viaud, Paimbœuf, Arthon-en-Retz (La Sicaudais), Saint-Père-en-Retz, Saint-Brevin-les-Pins, Saint-Michel-Chef-Chef, La Plaine-sur-Mer, Préfailles, Sainte-Marie-sur-Mer and Pornic. The coastal defensive sector of the pocket stretched over approximately of coastline. The Germans set up artillery batteries to defend the mouth of the Loire: A battery of two 240mm calibre guns