The Battle of Vimy Ridge was a military engagement fought as part of the Battle of Arras, in the Nord-Pas-de-Calais region of France, during the First World War. The main combatants were the Canadian Corps against three divisions of the German Sixth Army. The battle was part of the opening phase of the Battle of Arras, part Nivelle Offensive and took place from 9–12 April 1917. The objective of the Canadian Corps was to take control of the German-held high ground, along an escarpment at the northernmost end of the Arras Offensive. This would ensure that the southern flank could advance without suffering German enfilade fire. This listing covers Allied Powers and Central Powers formations and units involved in the battle. Although the Canadian side is well studied, historians have had trouble determining the exact dispositions of the German forces and even more trouble assessing the casualties it suffered in the battle. The Canadian Corps suffered 10,602 casualties; 3,598 killed and 7,004 wounded. The German Sixth Army suffered an unknown number of casualties with an approximate 4,000 men becoming prisoners of war. The significance of the Battle of Vimy Ridge is most strongly felt in Canada. Elsewhere the battle is principally noted as part of the much larger British offensive known as the Battles of Arras 1917. The historical reality of the battle has been reworked and reinterpreted, in a conscious attempt to give purpose and meaning to an event which came to symbolize Canada's coming of age as a nation. The idea that Canada achieved nationhood as a direct result of the experiences of the First World War, is an opinion widely held in military histories of Canada and also regularly appears in general histories. A portion of the former battleground is preserved memorial park and site of the Canadian National Vimy Memorial. Allied Powers forces Canadian Corps commander Lieutenant-General Sir Julian Byng had four attacking divisions, one division of reserves and numerous support units under his command. He was supported to the north by the 24th British Division of I Corps which advanced north of the Souchez river and by the advancing XVII Corps to the south. The 4th Canadian Division was responsible for the northern portion of the advance which included the capture of the highest point of the ridge followed by the heavily defended knoll known as "the Pimple" just north of the town of Givenchy-en-Gohelle.