 Operation Tractable was the final offensive conducted by Canadian and Polish troops , supported by one brigade of British tanks , as part of the Battle of Normandy during World War II . The goal of this operation was to capture the strategically important French town of Falaise and then the smaller towns of Trun and Chambois . This operation was undertaken by the 1st Polish Armoured Division and the First Canadian Army against Army Group B of the Wehrmacht as part of the largest encirclement on the Western Front during the Second World War . Despite a slow start and limited gains north of Falaise , novel tactics by the 1st Polish Armoured Division — under the command of Generał brygady Stanisław Maczek during the drive for Chambois — enabled the Falaise Gap to be partially closed by 19 August 1944 , trapping about 150 @,@ 000 German soldiers in the Falaise Pocket . 
