The 'Battle of Chambois' was fought between Allied and German forces during the last stage of the 'Battle of the Falaise Pocket' in France (18/20 August).

Before the battle, a pocket of German forces had come into existence around Falaise in the Calvados region of north-western France, where large parts of Generalfeldmarschall Walter Model’s Heeresgruppe 'B', in the form of SS-Oberstgruppenführer und Generalobest der Waffen-SS Paul Hausser’s 7^th Army and SS-Oberstgruppenführer und Generaloberst der Waffen-SS Josef Dietrich’s 5^th Panzerarmee (ex-Panzergruppe 'West') were encircled by formations of the Western Allies. The seizure of Chambois by US, Canadian and Polish forces signalled the final closure of the neck of the Falaise pocket on 21 August and the destruction of most of Heeresgruppe 'B'.

After the success of the 'Totalize' operation to the south of Caen on 8/9 August, Lieutenant General H. D. G. Crerar pushed his Canadian 1^st Army to the south. The 'Tractable' operation was then launched to break through the German line and capture the tactically important town of Falaise and then the smaller towns of Trun and Chambois, and thus to encircle substantial German formations.

On 18 August, Canadian forces captured Trun, while Generał brygady Stanisław Maczek’s Polish 1^st Armoured Division headed toward Chambois, just to the south-east of Trun, to complete the encirclement of 110,000 Germans in the Falaise pocket. Small corridors to the east of Chambois allowed modest numbers of Germans to escape the pocket and head toward the Seine river. At the same time, to the south of Chambois, Major General Raymond S. McClain’s US 90^th Division pushed to the north in order to help complete the closure of the pocket at Chambois. On the morning of 19 August, St Lambert sur Dives was taken by Canadian forces, and at 12.00 Polish forces attacked towards Chambois and against German positions on what was known as Hill 262, to the north-east of Chambois. Polish forces then attacked the outskirts of Chambois, which had been heavily shelled and was in ruins with German soldiers from various battered units flowing into the area.

To the east of Chambois, Polish and US forces linked to complete the closure of the Falaise pocket. The Allies continued to attack retreating elements of the 7^th Army and 5^th Panzerarmee and the 116^th Panzerdivision, the last under the temporary command of Oberst Gerhard Müller. A German counterattack organised by Hausser on 20 August failed to break Polish lines, but did allow more German troops to escape from the pocket. German troops and vehicles were trapped on the congested narrow roads and were easy prey for Allied artillery and air attacks. Late on August 20, Chambois finally fell to Polish forces and the Falaise pocket was almost totally sealed on 21 August 21 with some 50,000 Germans trapped inside it.

The fighting for the Falaise pocket resulted in the destruction of most of Heeresgruppe 'B' in the area to the west of the Seine river, and this opened the way to Paris and the Franco-German border for the Allied armies on the Western Front. Remnants of German formations and units retreated eastward in the direction of the Seine river but had to abandon much of their heavy armour and artillery. Hausser was wounded in the jaw during the battle but escaped the encirclement, and was succeeded in command of the 7^th Army in quick succession by General Hans Freiherr von Funck (21/33 August), General Heinrich Eberbach (22/31 August) and, after Eberbach had been taken prisoner, General Erich Brandenberger.