First Canadian Army The First Canadian Army was the senior Canadian operational formation in Europe during the Second World War . The Army was formed in early 1942 , replacing the existing unnumbered Canadian Corps , as the growing number of Canadian forces in the United Kingdom necessitated an expansion to two corps . By the end of 1943 Canadian formations in the UK consisted of three infantry division s , two armoured division s , and two independent armoured brigade s . The first commander was Lieutenant - General A . G . L . " Andy " McNaughton , who was replaced in 1944 by General H . D . G . " Harry " Crerar . Both had been senior artillery officers in the Canadian Corps in the First World War . Allied formations of other nationalities were added to the First Canadian Army to keep it at full strength . The Army ' s strength was 177 , 000 in all ranks at the end of 1942 . One year later it had grown to 242 , 000 . At the time of the invasion of Normandy on 31 May 1944 , it was 251 , 000 , of which 75 , 000 were in Italy . History . When the First Canadian Army was formed overseas in 1942 , Lieutenant - General McNaughton ' s aim was to keep the Canadian Army unified to lead the cross - channel assault on northwest Europe . Two brigades of the 2nd Division led the ill - fated Dieppe Raid in 1942 . Aside from this endeavour , the Army did not see combat until July 1943 . In 1943 , because the Canadian government wanted Canadian troops to see action immediately , the 1st Canadian Infantry Division , 1st Canadian Armoured Brigade , and 5th Canadian ( Armoured ) Division were detached from the Army for participation in the Italian Campaign . In early 1944 , the 3rd Canadian Infantry Division and 2nd Armoured Brigade were also detached to British I Corps to participate in the assault phase of the Normandy landings . II Canadian Corps became operational in Normandy in early July 1944 , as the 2nd Canadian Infantry Division landed . The First Canadian Army headquarters did not itself arrive in Normandy until mid - July , becoming operational 23 July 1944 just prior to 4th Canadian ( Armoured ) Division arriving on the Continent . The Army proper first went into action in the Battle of Normandy and conducted operations at Falaise ( e . g . Operation Totalize , Operation Tractable ) and helping close the Falaise pocket . After reaching the Seine , the objective of the first phase of Operation Overlord , the Army moved along the coast towards Belgium , with the Canadian 2nd Division entering Dieppe at the beginning of September . The critical Battle of the Scheldt in October and November opened Antwerp to Allied shipping . The First Canadian Army held a static line along the river Meuse ( Maas ) from December through February , then launched Operation Veritable in early February . By this point the Army , besides the II Canadian Corps , contained nine British divisions . The Siegfried Line was broken and the Army reached the banks of the Rhine in early March . In the final weeks of the war in Europe , the First Army cleared the Netherlands of German forces . By this time the First Division and Fifth ( Armoured ) Division as well as First Armoured Brigade had returned to the Army during Operation Goldflake and for the first time , both the I Canadian Corps and II Canadian Corps fought under the same Army commander . Makeup . The First Canadian Army was international in character . The size of Canada ' s military contribution on its own would likely not have justified the creation of a separate army - level command in North - West Europe , especially over the period when I Canadian Corps was away gaining valuable combat experience in Italy . However , both McNaughton and Crerar , backed up by the Canadian government , were successful in their lobbying to create a Canadian - led army enlarged with contributions from other Allied countries . In addition to II Canadian Corps ( which included the Canadian formations under command described above ) , other formations under command included the British I Corps , and the 1st Polish Armoured Division , as well as , at various times , American , Belgian , Dutch and Czechoslovak troops . The First Canadian Army in North - West Europe during the final phases of the war comprised the largest field army ever under the control of a Canadian general . Ration strength of the army ranged from approximately 105 , 000 to 175 , 000 Canadian soldiers to anywhere from 200 , 000 to over 450 , 000 when including the soldiers from other nations . The ' Maple Leaf Route ' was the designation of the army ' s Main Supply Route . The route was usually divided , into MAPLE LEAF UP and MAPLE LEAF DOWN , designating traffic to and away from the front , respectively . Order of battle . Second World War 1939 – 1945