Editing Battle of Vimy Ridge (section)

==Background==

===Vimy Ridge 1914–1916===
[[File:USMA - Battle of Arras - Vimy Ridge derivative.png|thumb|Location of the Battle of Vimy Ridge]]
Vimy Ridge is an [[escarpment]] {{cvt|8|km}} northeast of [[Arras]] on the western edge of the Douai Plain. The ridge rises gradually on its western side and drops more quickly on the eastern side. At approximately {{cvt|7|km}} in length and culminating at an elevation of {{cvt|145|m}} or {{cvt|60|m}} above the Douai Plains, the ridge provides a natural unobstructed view for tens of kilometres in all directions. The ridge fell under German control in October 1914 during the [[Race to the Sea]] as the Franco-British and German forces attempted to outflank each other through northeastern France.{{sfn|Boire|2007|pp=52–53}} The French [[Tenth Army (France)|Tenth Army]] attempted to dislodge the Germans from the region during the [[Second Battle of Artois]] in May 1915 by attacking their positions at Vimy Ridge and [[Notre Dame de Lorette]]. The French 1st Moroccan Division managed to briefly capture the height of the ridge but was unable to hold it owing to a lack of reinforcements.{{sfn|Boire|2007|p=56}} The French made another attempt during the [[Third Battle of Artois]] in September 1915 but only captured the village of [[Souchez]] at the western base of the ridge.{{sfn|Tucker|1996|p=68}} The Vimy sector calmed following the offensive with both sides taking a largely [[Live and let live (World War I)|live and let live]] approach. The French suffered approximately 150,000 casualties in their attempts to gain control of Vimy Ridge and surrounding territory.{{sfn|Turner|2005|p=8}}

===1916–1917===

{{see also|Tunnel warfare|German attack on Vimy Ridge}}

The French Tenth Army was relieved in February 1916 by [[XVII Corps (United Kingdom)|XVII Corps]] (Lieutenant-General Sir [[Julian Byng]]) and transferred to join in the [[Battle of Verdun]].{{sfn|Boire|1992|p=15}} The British soon discovered that German tunnelling companies had taken advantage of the relative calm on the surface to build an extensive network of tunnels and deep [[Mining (military)|mines]] from which they would attack French positions by setting off explosive charges underneath their trenches.{{sfn|Boire|2007|p=59}} The [[Royal Engineers]] sent specialist [[Royal Engineer tunnelling companies|tunnelling companies]] to the ridge to combat the German mining operations and German artillery and trench mortar fire intensified in early May 1916.{{sfn|Boire|2007|p=59}}{{sfn|Samuels|1996|pp=200–202}} On 21 May 1916, after shelling the British forward trenches and divisional artillery positions from eighty hidden batteries on the reverse slope of the ridge, the German infantry began {{lang|de|Unternehmen Schleswig Holstein}}, an attack on the British lines along a {{cvt|2000|yd}} front, to eject them from positions along the ridge. The Germans captured several British-controlled tunnels and mine craters before halting their advance and digging in.{{sfn|Samuels|1996|pp=200–202}}{{refn|The Germans had grown uneasy about the proximity of the British positions to the top of the ridge, particularly after the increase in British tunnelling and counter-mining.|group="Note"}} Small counter-attacks by battalions of the 140th and 141st Brigades took place on 22 May but were foiled.{{sfn|Samuels|1996|pp=200–202}} The Canadian Corps relieved [[IV Corps (United Kingdom)|IV Corps]] along the western slopes of Vimy Ridge in October 1916.{{sfn|Farr|2007|p=147}}