Battle of Hill 70
The Battle of Hill 70 took place in the First World War between the Canadian Corps and attached units against five divisions of the German 6th Army. The battle took place along the Western Front on the outskirts of Lens in the Nord-Pas-de-Calais region of France between 15 and 25 August 1917.
The plan was to inflict casualties, to draw German troops away from the 3rd Battle of Ypres and to make the German hold on Lens untenable. The Canadian Corps captured Hill 70 to establish defensive positions from which combined small-arms and artillery fire, some of which used the new technique of predicted fire, would inflict mass casualties on German counter-attacks. The Germans were prevented from transferring divisions to the Ypres Salient but did not bring in troops from other areas.
The Canadian Corps failed to enter Lens but German and Canadian assessments concluded that it succeeded in its attrition objective. The battle was costly for both sides and many casualties were suffered from extensive use of poison gas, including the new German Yellow Cross shell.
Background
Western front
By May 1917, the Nivelle Offensive, despite the successful opening of the Battle of Arras, had come to a disastrous conclusion with the French Army mutinies. On 30 April, as the French hesitated to continue the Second Battle of the Aisne, the commander of the British Expeditionary Force, Field Marshal Sir Douglas Haig, gave orders to the First Army, to advance towards Lens to gain a line from Méricourt to Sallaumines Hill, Lens and Hill 70. Horne already desired to cut off the salient containing Lens to shorten the front, while unwilling to risk a costly and slow frontal assault into the maze of ruins. The First Army was understrength after the Battle of Arras but since Operation Alberich, the German withdrawal to the Hindenburg Line, in March, there was some hope that the 6th Army could be manoeuvred out of Lens by gradual advances to capture the higher ground to the south, west and north of the city.On 7 May, Haig informed the British army commanders that the French had terminated the Nivelle Offensive and the strategy of returning to a war of manoeuvre. Operations to exhaust the powers of resistance of the German armies would resume by systematic, surprise attacks and when this was complete, the British would begin an offensive at Ypres to capture the Belgian coast and reach the frontier with the Netherlands. The objectives of the First Army were unchanged but instead of capturing ground around Lens to shorten the front, was to menace the German hold on Lens and the defences south of Lille, to divert and to weaken the 6th Army. The operations were not a diversion but a means to keep the First Army front active for as long as possible, to mislead the Germans as to British intentions in Flanders. On 8 May, Horne told the First Army corps commanders that
On 7 July, Haig gave orders that the Canadian Corps was to capture Lens to stop the 6th Army from sending troops north to Flanders.
Lens
From Vimy Ridge the ground declines about into the Douai Plain; the valley of the Souchez river is about wide and flows south-west to north-east through the south of the city of Lens. In 1914, the river had several road and rail bridges. By 1917, much of the city was derelict due to years of artillery bombardments, the ruins being natural strongpoints overlooked by crassiers and several hills, including Hill 70, Hill 65 and Sallaumines Hill forming a shallow, saucer-shaped depression in which the city lay. To the south-east, on terrain that is above sea level, Sallaumines Hill rises to. On the west side of Lens is Hill 65 north of the Souchez, which is steep-sided and gives a fine view of the city.To the north-west, on the east side of the Lens–Bethune road, is a hill about high with the suburb of Cité St Pierre on top. Hill 70 is north of the city and has a flat top, giving a fine view of the city and the ground to the north and east. The hill slopes gently towards Lens and there is a shallow depression between it and Cité St Pierre. The slopes of Hill 70 towards Cité St Auguste are steeper. Lens, Hill 70, Sallaumines and Sallaumines Hill to the south-east and their commanding views over the area and the city, fell under German control in October 1914, during the Race to the Sea. In September 1915, the British overran the hill during the Battle of Loos but it was recaptured by the Germans.
Local operations
Horne began to make plans for the capture of Lens during the Third Battle of the Scarpe. Horne wanted the Canadian Corps to continue its operations east of Vimy Ridge to capture Méricourt and La Coulotte, which would endanger the German defences of Sallaumines Hill, south-east of Lens, as I Corps north of the Souchez, with twelve tanks, captured Hill 65 and Hill 70. The attacks would envelop Lens on three sides and give forward observation officers sight of the German defences in the city, potentially to force the 6th Army to retire without the need for a frontal attack. In May, Holland had surveyed the I Corps front, noted the importance of Hill 70 and that the Germans would make great efforts to re-capture it.German counter-attacks could only be resisted if plenty of reserves and much artillery support were made available. Deliberate attacks to capture the high ground around Lens would meet the goals of the First Army despite its limited means. In May and early June, First Army units conducted eighteen raids and minor actions, moving the front line slowly eastwards over the Douai Plain. By 6 June, the First Army had captured all the high ground in the area, except that around Lens. I Corps was west of the city from the Souchez north to Hill 65, through Cité St Theodore and along the ridge of the 70-metre hill to the north of Cité St Pierre.
On 9 June Arthur Currie, the 1st Canadian Division commander, was promoted to command the Canadian Corps. On 10 June, Holland told Horne that only the capture of Hill 70 was important and suggested inflicting mass casualties by raids, bombardments and gas attacks, to create the impression that a big attack was imminent. The defenders would be kept guessing and have to move more troops and artillery to the hill, despite the inevitable losses. Horne doubted that the army had sufficient men and artillery for the task and arranged for the 46th Division, on the right of I Corps, to make preparations to take Hill 70 and the vicinity but only if reinforcements from GHQ were forthcoming.
While waiting, I Corps would capture Hill 65 and to south of the Souchez, the right flank divisions of the Canadian Corps and XIII Corps to the south would prepare to attack from Gavrelle to Oppy, Fresnoy, Acheville and Mėricourt, digging jumping-off trenches to simulate a threat to Lens from the south. The real attack was to come from the left flank of the Canadian Corps towards Sallaumines Hill and the east end of Avion. Success would trap the Germans in Lens between Sallaumines Hill to the south and Hill 70 to the north. If the 6th Army did not retire, the preparations by I Corps at Hill 70 would make it impossible to predict from which direction the next attack would come.
Affairs south of the Souchez
To create a threat to Lens, Horne intended that XIII Corps on the southern flank would attack to reach better positions between the villages of Gavrelle and Oppy by advancing the front line for on a front. The 4th Canadian Division on the left flank of the Canadian Corps south of the Souchez River and the 46th Division on the right of I Corps, north of the river, were to attack on a front of to eliminate a German salient from Avion to the west end of Lens and to occupy Hill 65. I Corps was to plan for an attack on Hill 70 with the 6th Division on the left flank. Horne expected that the operations would take place in early July but found that much of the best heavy artillery was to be sent to Flanders and brought forward the date to 28 June. The plans were reduced in scope; the XIII Corps scheme was retained but the attack either side of the Souchez was limited to the capture the German front line west of Avion and Hill 65; the Hill 70 plan was postponed.The morning of 28 June was dull, humid and storm clouds appeared in the south during the afternoon. The First Army artillery, assisted by Third Army guns en route to Flanders, began a bombardment along the army front from Gavrelle northwards to Hulluch. The simulation of a much bigger attack on Lens was enhanced by lightning, thunder and a downpour, which began at when the infantry advance began. The adjacent brigades of the 31st Division and the 5th Division had been bombarded in their jumping-off trenches at and had suffered 200 casualties before the advance began. The survivors moved so fast that when a German counter-barrage fell on no man's land three minutes later, the British were on the far side and suffered no harm. The attackers suffered few casualties, took and counted German soldiers. Gavrelle Mill and a new line was consolidated, despite the rainstorm, from which the areas to the north-east and east around Neuvireuil and Fresnes could be observed, along with Greenland Hill to the south-west.
Capture of Avion
Orders from the First Army HQ reached Currie on 12 June, who replied with a suggestion that the capture of Hill 65 was tactically desirable to gain observation over Lens and to deprive the Germans of reciprocal observation of the British rear. The capture of Avion could be replaced by a raid, to avoid the casualties of a permanent occupation. Preparations for attacks towards Avion would be more meaningful to German observers than the attack which followed. The suggested alternative was not well received by Major-General Hastings Anderson, the First Army chief of staff, because one purpose of the operation was to threaten Lille, which could only occur with the capture of Lens after the attack on Avion. The Canadian operation was a stage in the army plan, to be followed by an attack or feint towards Sallaumines Hill. A few days later, more artillery was transferred to Flanders and the Hill 70 attack was postponed.Further north, opposite the 4th Canadian Division and 46th Division, the German 56th Division had moved into reserve on 22 June to replace a division transferred to Flanders. The line-holding division had orders to retire from the salient to the Avion–Lens railway if pressed. The western slopes of Hill 65 had been occupied by the British on 24 June after a German retirement and patrols pushed forward towards Avion Trench, which was occupied early on 28 June. The 46th Division and the 4th Canadian Division made ready to resume their advance when the army barrage began at Most of Avion, Éleu-dit-Leauwette and the eastern slope of Hill 65 was captured as the 3rd Canadian Division formed a defensive flank along the Arleux–Avion road, joining with the 4th Canadian Division in Avion. Rain and flooding from the Souchez stopped patrols from probing the German main line of resistance in the north-eastern part of Avion and along a railway embankment about further on.