 It was a year before Horrocks recovered sufficiently to tell Alan Brooke , the Chief of the Imperial General Staff ( CIGS ) , that he was " very anxious to be given another corps " . Restored to the acting rank of lieutenant @-@ general in August 1944 , he was sent to France to assume command of XXX Corps during the cataclysm engulfing the trapped German 7th Army and 5th Panzer Army in the Falaise Pocket . Montgomery had been dissatisfied with the performance of the corps and its commander , Gerard C. Bucknall , since the landings in Normandy two months earlier . Horrocks retained control of XXX Corps during the advance through Belgium , taking Brussels , and at one point advanced 250 miles ( 400 km ) in only six days . Supplies were a constant concern , with the major French deep @-@ water ports still in German hands , and Allied supply lines stretching perilously back to the Normandy beaches . Montgomery 's 21st Army Group was by now operating 300 miles ( 480 km ) from its ports — twice the distance logistical planners had accounted for — so XXX Corps was diverted towards Antwerp to secure its docks and harbour . The city and port fell to the 11th Armoured Division in early September , but Montgomery halted XXX Corps for resupply short of the wide Albert Canal to the north of the city , which consequently remained in enemy hands . Horrocks regretted this after the war , believing that his corps might have advanced another 100 miles ( 160 km ) with the fuel available , although it is doubtful this could have been achieved without delays . Unknown to the Allies , at that time XXX Corps was opposed by only a single German division . The pause allowed the Germans to regroup around the Scheldt River , and by the time the Allies resumed their advance , General Student 's First Paratroop Army had arrived and set up strong defensive positions along the opposite side of the canal . The task of breaking the strengthened German line , which stretched from Antwerp to the North Sea along the Scheldt River , would fall to the First Canadian Army in the month @-@ long , costly Battle of the Scheldt . By mid @-@ September , XXX Corps had been diverted again , this time to the east . 
