The Capture of Westhoek (West corner, 10 August 1917) took place on the Gheluvelt Plateau near Ypres in Belgium, during the Third Battle of Ypres (31 July – 10 November 1917), in the First World War. The British Fifth Army attacked the Gheluvelt Plateau at the Battle of Pilckem Ridge (31 July – 2 August) but the German 4th Army had fortified its positions in the Ypres Salient since the Second Battle of Ypres (22 April – 25 May 1915). The British reached the first objective in the south and the second objective on the northern flank, losing some ground to German counter-attacks. A British attack due on 2 August was postponed because torrential rain from the afternoon of 31 July until 5 August washed out the battlefield.
The ground had been churned by artillery-fire into sloughs of mud, flooded shell craters, fallen trees and barbed wire. After several postponements, the attack was set for 10 August. British artillery fired a preparatory bombardment from Polygon Wood to Langemarck for the main attack due on 14 August but the German guns concentrated on the Gheluvelt Plateau. British counter-battery fire was hampered by low cloud and rain, which made air observation extremely difficult and shells were wasted on empty gun emplacements. Fresh divisions took over by 4 August but the front line troops had to be relieved every which exhausted all of the infantry by 10 August. The German 52nd Reserve Division, which had not been relieved after 31 July and the 54th Division, that had taken over on the northern flank of the Plateau by 4 August, were also exhausted.
The British attack on the right flank began well and some troops quickly reached their objectives. The 74th Brigade of the 25th Division on the left flank advanced fast and reached its objectives by The Germans in Westhoek were rushed but on the right flank, sniping and attacks by German aircraft caused an increasing number of British casualties. German artillery began an SOS barrage at from Stirling Castle to Westhoek. The foremost British infantry were cut off in the open and counter-attacked. Around fresh German infantry advanced behind a smokescreen and by nightfall, Inverness Copse and most of Glencorse Wood had been recaptured.
The 25th Division held on around Westhoek but lost killed, and more than The defeat of the 18th (Eastern) Division at Inverness Copse, Fitzclarence Farm and Glencorse Wood left German snipers and machine-gunners free to fire into the right flank of the 25th Division. German counter-attacks continued into the night but communication by SOS rockets, daylight lamps, carrier pigeons and runners enabled the British artillery accurately to bombard German troops as they assembled.
Background
Topography
Ypres is overlooked by Kemmel Hill in the south-west and from the east by low hills running south-west to north-east, with Wytschaete (Wijtschate) and Hill 60 to the south of Verbrandenmolen, Hooge, Polygon Wood and Passchendaele (Passendale). Wytschaete is from Ypres, at Hollebeke the ridge is distant and recedes to at Polygon Wood. Wytschaete is the highest point, about above the plain; on the Ypres–Menin road at Hooge, the elevation is about and at Passchendaele. The rises are slight, apart from the vicinity of Zonnebeke, which has a gradient of From Hooge and to the east, the slope is near Hollebeke, it is The heights are subtle and resemble a saucer lip around the city. The main ridge has spurs sloping east and the spur at Wytschaete, runs south-east to Messines, with a gentle slope to the east and a to the west. Further south is the muddy valley of the Douve river, Ploegsteert Wood (Plugstreet to the British) and Hill 63. West of Messines Ridge is the parallel Wulverghem (Spanbroekmolen) Spur, with the Oosttaverne Spur, also parallel, further to the east. The general aspect south and east of Ypres is one of low ridges and dips, gradually flattening northwards beyond Passchendaele into a featureless plain.
Possession of the higher ground to the south and east of Ypres gives ample scope for ground observation, enfilade fire and converging artillery bombardments. An occupier also has the advantage that the movement of artillery, reinforcements, supplies and stores can be screened from view. The ridge had woods from Wytschaete to Zonnebeke giving good cover, some being of notable size like Polygon Wood and those later named Battle Wood, Shrewsbury Forest and Sanctuary Wood. In 1914, the woods usually had undergrowth but by 1917, artillery bombardments had reduced the woods to tree stumps, shattered tree trunks and barbed wire, tangled on the ground and a mass of shell-holes; the fields in gaps between the woods were wide and devoid of cover. Most roads in this area were unpaved, except for the main ones from Ypres, with occasional villages and houses built along them. In 1914, the lowland west of the ridge had been a mixture of meadow and fields, with high hedgerows dotted with trees, cut by streams and ditches emptying into canals. The main road to Ypres from Poperinge to Vlamertinge is in a defile, easily observed from the ridge.
Prelude
German preparations
Fortification
The 4th Army (General Friedrich Sixt von Armin) was responsible for defence of the Western Front from Lille to the North Sea, which included the Ypres Salient. In early 1917, German corps had been renamed based on a corps headquarters, with fresh divisions coming under command as tired ones were withdrawn rather than the previous permanent establishment of divisions. The IX Reserve Corps became and held a front south of the Menin road with three divisions holding the front line () and three (specially trained counter-attack) divisions in reserve. The III Bavarian Corps was renamed Gruppe (group) Ypres and held of front, from the Menin road to the Gheluvelt plateau and Pilckem to the north, with three front divisions and two divisions. The divisions were kept out of sight behind the Menin and Passchendaele ridges and further back were four more divisions; beyond were another two divisions in army group reserve.
The Germans were apprehensive of a British attempt to exploit the victory over at Messines, with an advance to the Tower Hamlets (Bassevillebeek) spur beyond the north end of the ridge. Since early 1917, there had been three German defensive positions behind the front line. The ran from Bixschoote in the north, behind Pilckem Ridge and south across the Gheluvelt Plateau. The began at Langemarck, ran south to Gravenstafel then crossed the Gheluvelt Plateau to Zandvoorde, east of Messines Ridge. The (Flanders Position) had been built earlier in the year, along Passchendaele Ridge, south across Gheluvelt Plateau behind Polygon Wood, in front of Becelaere, across the Menin road and south to the Lys (Leie) river. Because of the flat ground and high water table hundreds of pillboxes and blockhouses rather than deep dugouts, had been built above ground and camouflaged with mud and turf. The many stone farmhouses dotted around had also been fortified; from two to forty men could be accommodated in the concrete and steel shelters, immune to anything smaller than a hit by an 8-inch shell.
On 9 June, Rupprecht proposed withdrawing to the in the area east of Messines; construction of defences began but were terminated on 14 June after Colonel Fritz von Loßberg was appointed as the new Chief of Staff of the 4th Army. Loßberg rejected the withdrawal to the and ordered that the front line be held rigidly. The , along Passchendaele Ridge east of the , would become the and a new would branch off north of Passchendaele run south through Terhand and west of Menin to the Lys. Construction of from Moorslede to Westroosebeke, behind Passchendaele Ridge to Dadizeele and west of Menin on the Lys was also begun. By July, the area east of Ypres was defended by the front position, the (second position), (third position), (fourth position), (fifth position) and (sixth position, under construction).
Debate among the German commanders continued and on 25 June, Ludendorff suggested that be withdrawn to the , leaving only outposts in the . On 30 June, Kuhl suggested a withdrawal to the along Passchendaele Ridge, meeting the old front line near Langemarck to the north and Armentières in the south. A withdrawal would avoid a hasty retreat from Pilckem Ridge and force the British into a time-consuming redeployment. Loßberg disagreed, because the British would launch a broad front attack, making a local withdrawal pointless, the ground east of the line was easy to defend, Menin Road Ridge could be held and that Pilckem Ridge deprived the British of ground observation over the Steenbeek valley, while German observation of the area from Passchendaele Ridge allowed infantry to be supported by observed artillery fire.
Infantry organisation
The 4th Army operation order for the defensive battle was issued on 27 June. The system of defence in depth began with a front system (first line) with breastworks , about apart, garrisoned by the four companies of each front battalion with listening-posts in no-man's-land. About behind these works, was the forward battle zone () backed by the (second or artillery protective line). The support battalions comprised a company to hold strong-points and three (storm companies) to counter-attack from the back of the , half based in the pillboxes of the to provide a framework for the re-establishment of defence in depth, once an attack had been repulsed. Dispersed in front of the line were divisional (Sharpshooter) machine-gun nests, called the (strongpoint line).
The marked the front of the main battle zone () which was about deep, containing most of the field artillery of the front divisions, behind which was the (third line); in its pillboxes the reserve battalions of the front-line regiments were held back for counter-attacks. From the back to was a rearward battle zone () containing support and reserve assembly areas for the divisions. The failures at Verdun in December 1916 and at Arras in April 1917, had given more importance to these areas, since the had been overrun during both offensives and the garrisons lost. It was anticipated that the main defensive engagement would take place in the with the reserve regiments and divisions advancing against attackers who had been slowed and depleted by the forward garrisons.
The leading regiment of an division was to advance into the zone of the front division (), with its other two regiments moving forward in close support. divisions were accommodated behind the front line and began their advance to assembly areas in the , ready to intervene in the with an instant-immediate counter-thrust (). Loßberg rejected elastic defence in Flanders, because there was little prospect of operational pauses between British attacks because the British had so much artillery and ammunition. A trench garrison which retired quickly became disorganised and could not counter-attack, losing the sector and leaving the flanks of neighbouring formations in the air. Loßberg ordered that the front line was to be fought for at all costs, with immediate counter-attacks to recapture lost sectors.
Front line troops were not expected to cling to shelters but leave them as soon as the battle began, moving forward and to the flanks to avoid artillery-fire and to counter-attack. German infantry equipment had recently been improved by the arrival of machine-guns (tactical equivalent of the British Lewis gun) per regiment. The of eight men was augmented by a crew of four men, to become a , the becoming a . The extra firepower gave German infantry more means for fire and manoeuvre tactics; of the front line garrison were formed into and the other were concentrated in , in the forward battle zone. The contained of the and in divisional reserve and the local division (composed of formations), was based in the rear positions.
1–9 August