The Battle of Pilckem Ridge (31 July – 2 August 1917) was the opening attack of the Third Battle of Ypres in the First World War. The British Fifth Army, supported by the Second Army on the southern flank and the French (First Army) on the northern flank, attacked the German 4th Army, which defended the Western Front from Lille northwards to the Ypres Salient in Belgium and on to the North Sea coast. On 31 July, the Anglo-French armies captured Pilckem (Flemish: Pilkem) Ridge and areas on either side, the French attack being a great success. After several weeks of changeable weather, heavy rain fell during the afternoon of 31 July.
In the XIX Corps area in the centre and on the right of XVIII Corps, three reserve brigades advanced from the black line to the main objective (green line) and pressed on towards the red line, the furthest that exploitation on local initiative had been allowed for in the plan. It began to rain, cutting off the advanced British troops from view, just as German regiments from specialist (counter-attack) divisions advanced over Passchendaele Ridge. To avoid being rolled up, the reserve brigades retreated, suffering many casualties, through the green line to the black line, which the British artillery-observers could still see; the German infantry were prevented from advancing further by massed artillery and small-arms fire.
A substantial amount of ground had been captured by the British and French, except on the Gheluvelt Plateau on the right flank, where only the blue line (first objective) and part of the black line (second objective) were captured. A large number of casualties were inflicted on the German defenders during the attack and were taken; the German divisions recaptured some ground from the Ypres–Roulers railway northwards to St Julien, forcing the British back to the black line. For the next few days, both sides made local attacks to improve their positions, much hampered by the deluges. The rains had a serious effect on operations in August, causing more problems for the British and French, who were advancing into the area devastated by artillery fire and partly flooded by the unseasonable rain.
A local British attack on the Gheluvelt Plateau on 2 August was postponed several times because of the weather until 10 August and the second big general attack, due on 4 August, did not begin until 16 August. The green line objectives on the Plateau were not captured until the Battle of the Menin Road Ridge on 20 September, after the principal role in the offensive was transferred to the Second Army and three weeks' sunshine and fresh breezes dried much of the ground. The Third Battle of Ypres became controversial while it was being fought, with disputes about the predictability of the August deluges and for its mixed results, which in much of the writing in English is blamed on apparent misunderstandings between Gough and Haig and on faulty planning, rather than on the resilience of the 4th Army.
Background
Strategic background
Operations in Flanders, Belgium had been desired by the British Cabinet, Admiralty and War Office since 1914. In January 1916, Haig ordered General Henry Rawlinson to plan an attack in the Ypres Salient. The need to support the French army during the Battle of Verdun December 1916 and the demands of the Somme battles November 1916, absorbed the offensive capacity of the British for the rest of the year. Marshal Joseph Joffre was replaced as the French Commander-in-Chief by General Robert Nivelle in December, who planned a breakthrough offensive by the French armies on the Western Front during the spring of 1917, to return to a war of manoeuvre and a decisive victory. The Nivelle Offensive began on 9 April with the British Battle of Arras, followed on 16 April by the French Second Battle of the Aisne. The British attack was a big success but the French plan to defeat decisively the (German army in the west) was a strategic failure. Morale in the French armies collapsed, mutinies occurred and Nivelle was replaced by General Philippe Petain.
While the French recuperated, offensive action on the Western Front could only come from the BEF and in June 1917, the principle of a Flanders campaign was reluctantly approved by the British War Cabinet. On the French sector, Petain intended to maintain an active defence and planned three limited (battles of recovery) lavishly to be supported with artillery, aircraft and manpower, sufficient to guarantee success and restore morale. In early June, at about the same time as the British attack on Messines Ridge, the Sixth Army would attack on the Aisne front. In Flanders, the First Army (General François Anthoine) was to participate in the British Flanders offensive and in mid-July, the Second Army would attack at Verdun, as the main Flanders offensive began. In early June, the crisis in the French armies led to the postponement of the Sixth Army attack on the Chemin des Dames but during June and July, the concentration of the First Army north of Ypres continued.
British plans 1916–1917
In late 1916, the Second Army commander, General Herbert Plumer was ordered to plan an attack out of the Ypres Salient but Haig was dissatisfied with the limited scope of the plan to capture Messines Ridge and Pilkem Ridge further north. In early 1917, Haig calculated that the Nivelle Offensive would force the Germans out of Belgium or that the 4th Army in Flanders would give up divisions to reinforce the armies further south. Plumer revised the plan to capture Messines and Pilckem ridges and advance onto the Gheluvelt Plateau; a later attack would capture the Plateau, Passchendaele and beyond. The plan required and far more artillery than the BEF possessed.
At General Headquarters (GHQ) Colonel George Macmullen proposed to capture the Gheluvelt Plateau with a massed tank attack but a reconnaissance in April, found that narrow defiles between three woods on the Plateau and broken ground obstructed the approaches. Tanks would have to detour north of Bellewaarde lake to Westhoek, then wheel right at the . Plumer produced another plan to take Messines Ridge and the west end of the Gheluvelt Plateau, followed by the capture of Pilckem Ridge. The Fourth Army commander, General Henry Rawlinson, proposed to take Messines Ridge first, then the Gheluvelt Plateau and Pilckem Ridge within
On 14 February, Macmullen submitted the GHQ 1917 plan and on 7 May, Haig set 7 June for the attack on Messines Ridge, the Flanders offensive to begin some weeks later. A week after the Battle of Messines Ridge, Haig informed the army commanders that the strategy was to wear down the 4th Army, secure the Belgian coast and advance to the Dutch frontier. Passchendaele Ridge was to be taken and the advance continued to Roulers (Roeselare) and Thourout, to cut the Bruges (Brugge) to Kortrijk railway that supplied the 4th Army from Ypres to the Belgian coast. Once the railway was cut, the Fourth Army would attack along the coast, combined with an amphibious landing (Operation Hush) in support of the main advance, along with the Belgian army in between. On 13 May, Haig appointed General Hubert Gough to command the Flanders offensive and Macmullen gave Gough the GHQ 1917 plan.
Prelude
Allied preparations
Gough met the corps commanders in June and the third objective of the GHQ 1917 plan, including the German (third position) was added to the first day objectives. A fourth objective (red line) was added as the limit of advances that could be made on local initiative if the German defence collapsed in places. Five divisions from the Second Army, nine divisions and a brigade of the Fifth Army and two divisions from the French First Army were to attack. A preparatory bombardment was planned from 16 to 25 July and the Second Army was to capture outposts in the Warneton line, to simulate an advance beyond Messines Ridge and stretch the German defence. The Fifth Army was to attack along a front from Klein Zillebeke northwards to the Ypres–Staden railway, the French I Corps on the northern flank attacking with two divisions, from the Fifth Army boundary to the flooded area just beyond Steenstraat. Infantry trained on a replica of the German trench system, built using information from aerial photographs and trench raids; some platoons had specialist training for attacking pillboxes and blockhouses.
The (fourth position), was behind the front line, well beyond the fourth objective (red line). Behind were and . In his Operation Order to the corps commanders of 27 June, Gough gave the green line as the main objective and that patrols of fresh troops were to probe towards the red line, to exploit any German disorganisation or collapse. The plan was more ambitious than the plan devised by Plumer for an advance of on the first day and Major-General John Davidson, the BEF Director of Operations, complained of "ambiguity as to what was meant by a step-by-step attack with limited objectives". Davidson suggested an advance of no more than , to increase the concentration of British artillery-fire. Gough replied that temporarily undefended ground should be occupied, which was more likely in the first attack, with its longer preparation than later attacks; after discussions at the end of June, Haig endorsed the Fifth Army plan.
Aerial preliminaries +Weather26–30 July Date Rainmm °F 26—75 27—75 28—78 2911.569 300.565 A planned slow build-up of Allied air activity over the Ypres Salient was changed to a maximum effort after a weather delay on 11 July, due to the effectiveness of the reply by the . The Germans had been sending larger formations into action and on 12 July, a record amount of air activity occurred. Thirty German fighters engaged Royal Flying Corps (RFC) and French fighters of the in a dogfight lasting an hour, the RFC losing nine aircraft and the fourteen. The Germans resisted the British and French air effort until the end of July, when their losses forced a change to more defensive tactics. On 1 July, the opening attack was postponed at the request of Anthoine as the French needed more time to prepare artillery emplacements. On 7 July, Gough asked for another postponement of five days; some British heavy artillery had been lost to the German counter-bombardment, some had been delayed and bad weather had hampered the programme of counter-battery fire. Haig agreed to delay until 28 July and then Anthoine requested another postponement because the poor weather had slowed his artillery preparation. After Gough supported Anthoine, Haig reluctantly agreed to wait until 31 July, despite endangering Operation Hush, which had to catch the high tides from 7 to 8 August; a delay might force a postponement for a month.
Allied plan
The set-piece attack was to begin with an advance by the Second Army on the right towards the Warneton line () with parts of five divisions to red, blue and green lines (objectives) on a front. The Fifth Army was to advance through the German front position, the (second position) and (third position) to the blue, black and green objective lines, which were about distant, at any of which a halt could be called depending on German resistance. Patrols from the reserve brigades were to advance towards the red line (fourth objective) further on, at the discretion of divisional commanders, if the German defence opposite had collapsed. The Fifth Army had guns and guns, with support from the and mortars of the French First Army on the northern flank and of X Corps in the Second Army to the south. Gough also intended to use to support the attack, with another reserve. Gough had five cavalry divisions and a cavalry brigade was to be deployed if XIV Corps reached its objectives.