Battle of the Menin Road Ridge

The Battle of the Menin Road Ridge, sometimes called "Battle of the Menin Road", was the third British general attack of the Third Battle of Ypres in the First World War. The battle took place 20–25 September 1917, in the Ypres Salient in Flanders on the Western Front. During the pause in Allied general attacks between late August and 20 September, the British changed some infantry tactics, by adopting the "leap-frog" method of advance, when waves of infantry stopped once they reached their objective, then consolidated the ground while other waves passed through the objective to attack the next one and the earlier waves became the tactical reserve. General adoption of the method was made possible when more artillery was brought into the salient and by increasing the amount of air support of ground operations and specialising the tasks of air defence, contact-patrol, counter-attack patrol, artillery observation and ground-attack. Optimism increased among German commanders, that the offensive had ended. Drier weather and extensive road repairs made it much easier for the British to move vast amounts of supplies forward from the original front line. Visibility increased except for frequent ground fog around dawn, which helped conceal British infantry during the attack, before clearing to expose German troop movements to British observation and attack. The British infantry succeeded in capturing most of their objectives and then holding them against German counter-attacks, inflicting many casualties on the local German defenders and the Eingreif Divisions sent to reinforce them, with massed artillery and small-arms fire. German defences on the Gheluvelt Plateau, which had been retained or quickly recaptured in July and August were lost and the British were able to attack again on 26 September.

Strategic background
The Kerensky Offensive by Russia in July had accelerated the disintegration of the Russian Army, increasing the prospect of substantial German reinforcements for the Western Front. The French attack at Verdun in August had inflicted a defeat on the German Army similar in extent to the Battle of Messines but morale in the French Army was still poor. In reports to the War Cabinet on 21 August and 2 September Sir Douglas Haig repeated his view that the British campaign at Ypres was necessary to shield the other armies of the Alliance, regardless of the slow geographical progress being made in the unusually wet weather of August.

Tactical developments
The German Fourth Army had defeated British attempts to advance to the black and green (second and third) lines set for 31 July in the centre of the battlefield and on the Gheluvelt Plateau, during the frequent weather interruptions in August. These defensive successes had been costly and by mid-August German satisfaction in their defensive achievements was accompanied by concern at the extent of German casualties. The rain, constant bombardments and British air attacks had also put great strain on the German defence between British attacks. After 31 July General Gough had ceased attempts to exploit opportunities created by the Fifth Army's attacks, which began a process of tactical revision, which with the better weather in September inflicted several costly defeats on the German Fourth Army. II Corps had been ordered to capture the rest of the black line on 2 August. The three northern corps of the Fifth Army were then to complete the capture of their part of the green line on 4 August, while XIV Corps and the French First Army crossed the Steenbeek on the left flank. The unusually wet weather had caused the attacks to be postponed until 10 August and the Battle of Langemarck (16–18 August); some of these objectives were still uncaptured after operations later in the month. Principal responsibility for the offensive was transferred to General Plumer on 25 August. The Second Army boundary was shifted north, into the area vacated by II Corps on the Gheluvelt plateau. Haig put more emphasis on the southern fringe of the plateau, by giving to the Second Army, the bulk of the heavy artillery reinforcements moved from Artois.

British offensive preparations
The General Headquarters staff of the British Expeditionary Force (BEF) quickly studied the results of the attack of 31 July and on 7 August sent questions to the army headquarters about the new conditions produced by German defence-in-depth. The German army had spread strong points and pillboxes in the areas between their defensive lines and made rapid counter-attacks with local reserves and Eingreif divisions, against Allied penetrations. Plumer issued a preliminary order on 1 September which defined the Second Army area of operations as Broodseinde and the area southwards. The plan was based on the use of much more medium and heavy artillery, which had been brought to the Gheluvelt Plateau from VIII Corps, on the right of the Second Army and by removing more guns from the Third and Fourth armies, which were further south in Artois and Picardy.

The increased amount of heavy artillery was to be used to destroy German concrete shelters and machine gun nests, which were more numerous in German "battle zones", than the "outpost zones" already captured and to engage in more counter-battery fire. Few German concrete pill-boxes and machine gun nests had been destroyed during earlier preparatory bombardments and attempts at precision bombardment before attacks had failed. The greater amount of medium and heavy artillery would also make the creeping barrage much heavier. The 112 heavy and 210 field guns and howitzers in the Second Army on 31 July, were increased to 575 heavy and medium and 720 field guns and howitzers for the battle, which was equivalent to one artillery piece for every five yards of the attack front and more than double the density in the battle of Pilckem Ridge.

Plumer's tactical refinements sought to undermine the German defence by making a shallower penetration and then fighting the principal battle against German counter-attack (Eingreif) divisions. By further reorganising the infantry's reserves, Plumer ensured that the depth of the attacking divisions roughly corresponded to the depth of local German counter-attack reserves and their Eingreif divisions. More infantry was provided for the later stages of the advance, to defeat German counter-attacks by advancing no more than 1500 yd before consolidating their position. When the Germans counter-attacked they would encounter a British defence-in-depth, protected by artillery and suffer heavy casualties to little effect, rather than the small and disorganised groups of British infantry that the Germans had driven back to the black line on the XIX Corps front on 31 July.

Minor operations
During the pause of early September both sides made numerous local attempts to improve their positions. On 1 September another determined German attack at Inverness Copse was repulsed after heavy fighting. Further north in the XIX Corps area, a battalion of the 61st Division tried to rush Hill 35 but only managed to take a small area and another attempt on 3 September failed. Next day a 61st Division attack on Aisne Farm was repulsed, as the neighbouring 58th Division took Spot Farm. On 5 September the 61st Division tried again at night, took a German outpost on Hill 35 and then lost it to a counter-attack. An attack from south of Hill 35 by the 42nd Division with the 125th Brigade and a battalion of the 127th Brigade took place on 6 September, after several days of practice barrages and a daylight reconnaissance by a small party, which probed to within 25 yd of Beck House; during the night the Germans sent up many flares and rockets and disclosed their barrage line and many undetected posts. The barrage schedule required four rounds per-gun-per-minute but the gunners fired up to ten shells a minute. The brigade attacked Iberian, Borry and Beck House Farms with two battalions forward and two in reserve, with the attached battalion acting as a carrying-party. Beck House was captured but fire from the south slope of Hill 35 stopped the rest of the attack with many casualties. The Germans recaptured Beck House at 10.45 a.m. and enfiladed the rest of the attackers, who were withdrawn except for the battalion on the extreme right, until another German counter-attack at 7.30 p.m. by fresh storm-troops forced it to retire, except from a small area 150 yd beyond the start line, which was abandoned next day; the division had c. 800 casualties. Another night attack by the 61st Division on Hill 35 failed. In the XVIII Corps area a company of the 51st Division made an abortive raid on Pheasant Trench.

Two battalions of the 58th Division conducted raids on 8 September and on 9 September the 24th Division (II Corps) withstood another determined German attack at Inverness Copse. On 11 September a night attack by a battalion of the 42nd Division failed to capture The Hut and a covering party for a group of soldiers working in no man's land discovered an Inniskilling Fusilier, who had lain out wounded since 11 August and subsisted on rations recovered from dead soldiers within reach. On 13 September the Guards Division was pushed back from the far side of the Broembeek and the Wijdendreft road. Next day a Battalion of the 42nd Division edged forward 100 yd and a battalion of the 58th Division attacked Winnipeg. In the evening a German counter-attack took ground towards Springfield. On 15 September a battalion of the 47th Division, under cover of a hurricane bombardment attacked and captured a strongpoint near Inverness Copse, fire from which had devastated earlier attacks in the vicinity, taking 36 prisoners. A battalion of the 42nd Division captured Sans Souci and the 51st Division launched a "Chinese" attack using dummies. A day later a German attack on the strongpoint captured by the 47th Division and renamed Cryer Farm, was defeated with many German losses and in the XIV Corps area another attack was stopped by small-arms fire on the 20th Division front. A party of the Guards Division was cut off near Ney Copse and fought its way out. Fighting then subsided until 20 September.

Plan of attack
Plumer planned to capture Gheluvelt Plateau in four steps, with an interval of six days between each to allow time to bring forward artillery and supplies, a faster tempo of operations than that envisaged by Gough in the planning before 31 July. Each step was to have even more limited geographical objectives, with infantry units attacking on narrower fronts in greater depth. The previous practice of attacking the first objective with two battalions and the following objectives with a battalion each, was reversed in view of the greater density of German defensive positions the further the attack penetrated. Double the medium and heavy artillery was available than that used on 31 July. Reorganisation in this manner had been recommended in a report of 25 August by the Fifth Army GOC R.A. Major-General H. Uniacke. The evolution in organisation and method would ensure that more infantry was on tactically advantageous ground, having had time to consolidate and regain contact with their artillery, before they received German counter-attacks. The British began a "desultory bombardment" on 31 August and also sought to neutralize the German batteries with gas in the days before the attack, including gas attacks on the three evenings before the assault. Aircraft were to be used for systematic air observation of German troop movements to and on the battlefield, to avoid the failures of previous battles where too few aircraft had been burdened with too many duties in bad weather.

The three-week pause allowed by Haig originated from Lieutenant-Generals Morland and Birdwood X and I Anzac corps commanders at a conference of 27 August. The attacking corps made their plans within the framework of the Second Army plan using General Principles on Which the Artillery Plan Will be Drawn of 29 August, which described the multi-layer creeping barrage and the use of fuze 106 to avoid adding more craters to the ground. The Second Army and both corps did visibility tests to decide when zero hour should be set and the use of wireless and gun-carrying tanks were discussed with Plumer on 15 September. X Corps issued its first Instruction on 1 September, giving times and boundaries to its divisions. The pattern for subsequent British attacks was established and Second Army orders and artillery instructions became routine, with an Attack Map showing the stages of attack and the timetable, the corps involved, corps movements and the time of attack were briefly noted. Like the attack of 31 July, nine British divisions from four corps were to participate on a front of approximately 10000 yd. The Second Army divisions had three times the ammunition and the Fifth Army divisions twice the ammunition than at Pilckem Ridge. In late August destructive fire by the heaviest artillery began on German strongpoints and counter-battery began early in September, although hampered by poor visibility.

The air plan incorporated some of the recommendations made after previous operations. Much work was done before the attack to standadize the methods used by battery commanders and artillery observation crews, which the experience of previous attacks had demonstrated to be necessary, as the informal liaison used hitherto had been made unworkable by the increase in the amount of artillery and aircraft. Wireless codes were standardized and better training introduced in schools in France and England for air-ground liaison. Attacks were to be made on German rest billets and railways, aerodromes and German infantry manoeuvring to counter-attack. 26 RFC squadrons were involved, including the two night-bombing squadrons which were supported by RNAS Handley-Pages from Coudekerque, beginning their operations the night before the attack. During the day German aerodromes were to be attacked periodically by small low-flying formations of fighters and from high-altitude by day bombers.

German defensive preparations
German defensive preparations: June–July 1917

Elastic defence had been rejected by the Fourth Army Chief of Staff, Major-General von Lossberg, who believed that a tactical withdrawal by trench garrisons would disoganise the counter-attacking reserves, leading to the loss of the sector concerned and danger to flanking units. Lossberg ordered the front line of sentry groups (Postengraben) to be held rigidly; British attacks would exhaust themselves and then be repulsed by local German reserves or Eingreif divisions if needed. Lossberg also judged that there was little prospect of British attacks being delayed by their need to move artillery forward and build supply routes. The British had a huge mass of artillery and the infrastructure necessary to supply it with ammunition, much of it built opposite Flandern I in the period between the attack at Messines and 31 July.

Lossberg's methods had succeeded on the front of XIX Corps in 31 July and against II Corps on the Gheluvelt Plateau on 31 July and during August, although the counter-attacks had been stopped in their turn by British artillery fire, when they reached areas where observation and communications between British infantry and artillery had been restored. Ludendorff later wrote that losses in the August battles had been unexpectedly high. The pause in British operations in early September helped to mislead the Germans. General von Kuhl (Chief of Staff, Army Group Crown Prince Rupprecht) doubted that the offensive had ended but by 13 September had changed his mind. Despite Kuhl urging caution, two divisions, thirteen heavy batteries and twelve field batteries of artillery, three fighter squadrons and four other air force units were transferred from the German Fourth Army. In the area about to be attacked, the Fourth Army had six ground-holding divisions backed by three Eingref divisions and 750 guns.

Second Army
The 19th Division in IX Corps covered the southern defensive flank of the attack front against the German 9th Reserve and 207th divisions, on a 1600 yd front from the Comines canal to Groenenburg Farm on the west slope of the Bassevillebeek valley. The six attacking battalions of the 58th Brigade on the right and the 57th Brigade on the left and their supporting battalions had a difficult approach. The 58th brigade battalions had to make their way through the obstructions of Opaque Wood and Imperfect Copse and then at midnight it began to rain until 5:00 a.m.. Zero hour was decided according to the weather and the time of 5:40 a.m. was passed forward at 1:45 a.m. so all ranks had to lie quiet in the rain for more than three hours. Around dawn a heavy mist formed and at 5:40 a.m. the barrage began. On the right the short advance to the first objective (red line) was met with opposition from dug-outs south-west of Hessian Wood, Jarrocks Farm, Pioneer House and a small wood nearby. Heavy machine-gun fire was also encountered from Hollebeke Château and the railway embankment. The right battalion reached the objective on time but the two to the left had many casualties and lost touch with their flanking units and the barrage, until the pause on the red line (first objective) allowed them to reorganise, mop-up and regain touch with units which had lost direction. The third battalion on the left was still held up by Hessian Wood so a defensive flank was formed facing north.

The 57th Brigade advanced to the red line with slight opposition on the right while the two battalions on the left had to cross an extremely boggy area which slowed them and stopped them from keeping up with the barrage. The delay resulted in them being caught by machine-gun fire from dug-outs near Top House while bunched up because of the heavy going. The red line (second objective) which here was little different to the first objective (green line) was reached and two platoons from each attacking company moved up ready to advance to the blue line (final objective) which began at 6:24 a.m. The second and final lines (red and blue) were contiguous on the right from Hessian Wood but the Germans defending the wood were still fighting when the advance was due to resume. Two companies of the right hand battalion managed to advance after suffering many losses and then a platoon went to assist the centre battalion. A number of dug-outs were cleared and 50 prisoners were taken, which enabled the centre battalion to get into the north end of the wood and gain touch with the left-hand battalion in the south-western corner. On the front of the 57th Brigade, opposition at Wood Farm and Belgian Wood was overrun by a bayonet charge and the blue line (third objective) reached on time. During this advance machine-gun sections and a battalion liaison detachment of the 39th Division pushed forward to North Farm, which was captured with four machine-guns and 29 prisoners. At 8:10 a.m. the protective barrage lifted 200 yd and patrols were sent forward to establish outposts and to clear the area of remaining German troops; Moat Farm and Funny Farm were mopped-up. Consolidation was begun despite machine-gun fre from Hollebeke Château, the green line (first objective) was dug-in and the ground forward to the blue line (final objective) defended in depth by posts. A German counter-attack was attempted at 7:30 a.m. and "annihilated" by small-arms and artillery fire.

In X Corps to the north, the 39th Division on the right, prolonged the southern defensive flank, from Groenenburg Farm northwards down the slope to the Bassevillebeek. The division suffered badly from German fire, as it advanced 800 yd to its objective, from hidden dug-outs in the area further north, which had already stopped the 41st Division. When the division reached its objective it swung back its left flank to link with the right hand brigade of 41st Division. The main attack was made by X Corps and 1st Anzac Corps on a 4000 yd front on the Gheluvelt plateau. Steady pressure in early September by the 47th Division, had advanced the British front line near Inverness Copse for a considerable distance, which made better jumping-off positions for the attack by I Anzac Corps. The four divisions advanced behind a creeping barrage of unprecedented weight. The increased amount of artillery allowed the heavy guns to place two belts of fire beyond the two from the field artillery; a machine-gun barrage in the middle made five belts of fire, each 200 yd deep. The creeping barrage started quickly, lifting 50 yd every two minutes and this allowed the British infantry to surprise the German outpost garrisons, while the Germans were still in their shelters, by looming out of the mist. After four lifts, the barrage slowed to 100 yd every six minutes. Most German troops encountered were so stunned by the bombardment, that they were incapable of resistance and surrendered immediately, despite few of the concrete pill-boxes and Mebu shelters being destroyed by the British artillery. In the few areas where the German defenders were capable of resisting, they inflicted heavy losses but were quickly outflanked in the mist. The new system of local reserves allowed the British to maintain momentum despite local checks.

The 41st Division had to advance across the Bassevillebeek valley against the right of the German 9th Division and the left of the Bavarian Ersatz Division to capture Tower Hamlets spur. The advance was hampered by overnight rain, which affected the valley more than the plateau to the north. Fire from camouflaged German machine-gun nests in the valley caused confusion and delay in the British infantry and the barrage was lost. The Bassevillebeek stream in the valley was eventually crossed, with the 122nd Brigade struggling forward and the 124th brigade held up near the British front line, by numerous machine-guns in the Quadrilateral, fortifications in three ruined cottages inside a digging 400 x at the south end of the spur. The Quadrilateral commanded the western approach to the spur and the rise north to the pill-boxes at Tower Hamlets. The left hand brigade of the division reached the third objective and threw back its right flank to the brigade on the right, which had advanced just beyond the second objective and then joined the left flank of 39th Division. Despite the failure to capture Tower Hamlets and parts of the two leading battalions of 124th brigade running away before being rallied, two dead and three wounded battalion commanders, the division defeated all German counter-attacks during the day.

The 23rd Division was held up for a short time by a German strong point in Dumbarton Wood, which had been missed by the barrage and caused many casualties. Despite the delay and the difficulty of navigating through clouds of dust and smoke, caused by the barrage and the marshy ground north of Dumbarton Lake, the first objective was reached a few minutes after the barrage and consolidated along the source of the Bassevillebeek. 69th Brigade on the left managed to get through Inverness Copse but German troops emerged from cover and fired on the troops behind, as they moved up to attack the second objective, causing severe losses before they were killed or captured. The troops who had been severely reduced in numbers, following on through the copse, were still able to capture a line of German fortifications along Menin Road, north of the hamlet of Kantinje Cabaret. Of four tanks attached for the attack along Menin Road, one bogged early and the infantry advance was too swift for the other three tanks to keep up. One tank was knocked out on the road and the other two carried ammunition and equipment to the troops at the final objective.

The 1st Australian Division on the right of I Anzac Corps, advanced on a 1000 yd front north of the Menin Road, with its right aimed at Fitzclarence Farm against part of the Bavarian Ersatz Division and most of the 121st Division. The Australians passed through Glencorse Wood, which had changed hands twice in August, quickly suppressing German resistance. The Germans at Fitzclarence Farm were kept under cover by rifle grenade fire, while other groups got behind and rushed the garrison, taking 41 prisoners. Infiltration was also used against German machine-gunners in concrete shelters, in the sunken road in the north end of the wood, who had caused many casualties. Close reserves worked behind the shelters, fought their way in and killed or captured the garrison. Nonne Bosschen was crossed by moving along the edges of shell craters, the second objective along the west edge of Polygon Wood being reached on time at 7:45 a.m. The Wilhelm (third) Line pill-boxes and Mebu shelters were captured quickly, while the German defenders were dazed by the bombardment and unable to resist. Few accounts survive from the Bavarian Ersatz Division companies holding the ground either side of the Menin road, as they were quickly overwhelmed by the 23rd and 1st Australian divisions. Machine-gun fire was heard from the Albrecht (second) Line at 8:30 a.m. but by 9:00 a.m. the British were well on the way to the Wilhelm (third) Line.

The 2nd Australian Division attacked with two brigades, one either side of the Westhoek–Zonnebeke road, against the German 121st Division, down the Hanebeek valley to the near bank. The German outpost garrisons were surprised and overrun. On the far side of the stream the advance overwhelmed the Germans who mostly surrendered en masse. Visibility began to improve to 200 – and on breasting the rise, machine-guns in Albert and Iron Cross redoubts in the Wilhelm (third) Line on Anzac House spur, the next rise to the east, were blinded by smoke grenades, at which the garrisons ran off. Further to the left, Anzac House, an important German artillery observation post overlooking the Steenbeek valley to the north, was captured as the garrison tried to engage the Australians by moving their machine-guns outside. As the divisions on the Gheluvelt plateau reached their second objective at 7:45 a.m., a breeze blew away the mist and revealed the magnitude of their achievement. The British had carried the defences which had held them up through August and had gained observation all the way to Broodseinde.

No German counter-attacks were mounted in the two hours that the British spent consolidating the second objective, as the creeping barrage stood for fourteen minutes in front of the second objective, then advanced 2000 yd before returning to the new British front line and then advancing again, to lead the British troops to the third objective. German counter-attacks were stopped before they reached the new British outposts. The German artillery only managed to fire a disjointed and sparse barrage, which did little to obstruct the troops ready to advance to the third objective as they moved up but snipers and long-range machine-gun fire began to harass the troops consolidating the second objective. Local operations were mounted to stop sniping, using the methods that had been so successful earlier in the morning, leading to Black Watch Corner at the south-west of Polygon Wood and Garter Point east of Anzac House and other strong-points being captured.

At 9:53 a.m. the barrage resumed its forward movement towards the third objective, another 300 – away. The 23rd Division had to fight forward through pill-boxes hidden in ruined cottages along the Menin Road, concrete shelters in Veldhoek and a hedgerow in front of it, before the German garrisons retreated. The left brigade was held up by a dozen pill-boxes in the Wilhelm (third) Line until noon, which caused the division many losses but the ground at the final objective proved to be dry enough for the troops to dig in. The two Australian divisions reached the third objective in half an hour, finding the Germans in those strongpoints not subdued during the halt on the second objective as stunned as those met earlier in the day. Strafing by eight German aircraft, (one of which was shot down by ground fire) and some shelling by German artillery caused minor losses, as the Australian divisions consolidated captured trenches and shell holes in their new front line.

Fifth Army
The British Fifth Army attacked on the left of the Second Army, V Corps on the right to capture the Wilhelm (third) Line, XVIII Corps in the centre, to finish the capture of the line from Schuler Farm to Langemarck and then advance 500 - 800 yd east towards Poelcappelle; XIV Corps formed the northern flank with 20th Division. V Corps had more field guns than the I Anzac Corps to the right and fewer heavy guns so only three barrage belts were possible. A creeping barrage by 18-pdr field guns was to move at the same speed as that of the Second Army. 18-pdr and 4.5-inch howitzer fire were to comb the area in front of the creeping barrage, from 100 - 400 yd deep and a neutralizing barrage by 6-inch howitzers and 60-pdr guns was to sweep ground 450 - 1200 yd in front of the creeping barrage. Artillery not needed for counter-battery fire was to put standing barrages on the most dangerous German positions, like Hills 37 and 40 and the German assembly areas in the dips behind Zonnebeke and Gravenstafel.

9th and 55th Divisions of V Corps were to attack on fronts of 1800 yd over ground held by the right of the German 121st Division and the 2nd Guards Reserve Division, which had also changed hands twice in August. The large numbers of strong-points, pill-boxes and fortified farms east of the Hanebeek and Steenbeek streams were mostly intact, despite numerous attempts to smash them with artillery fire. The artillery brought to the Ypres salient in September went to the Second Army so the Fifth Army adopted a new infantry formation, where moppers-up were reorganised into small groups of up to half a platoon, moving with the leading assault waves to capture specific strong-points and then garrison them. XVIII Corps adopted the same practice, which became standard in the Fifth Army soon after the battle.

The 9th Division was confronted by the morass of the Hanebeek valley, where the stream had been choked by frequent bombardment and turned into a swamp and water-filled shell-holes. Both brigades sent two battalions forward to the first objective and leap-frogged two more through them to take the final objective. Hanebeek Wood on the right was barraged with smoke and high-explosive shell rather than shrapnel, except for a lane along which a company was able to move behind the wood. When the artillery fire moved beyond the wood it was rushed from both directions and captured with fifty prisoners and four machine-guns. The South African Brigade on the left did the same thing at Borry Farm. In the mist the strong points were easily overrun except for four pill-boxes around Potsdam House, which were eventually attacked on three sides and captured, after inflicting heavy casualties on the attackers. Delays caused by machine-gun nests dug in along the Ypres–Roulers railway did not stop the division reaching the first objective as the barrage began to creep forward again at 7:08 a.m. At 7:08 a.m. when the 9th Division began the advance to the final objective, the right hand brigade found only minor opposition. The South African Brigade on the left was badly hit by German machine-gun fire from Hill 37, as delays to the 55th Division meant that it was well short of the hill. The South Africans managed to capture Bremen Redoubt and Waterend House in the Zonnebeek valley and extend a defensive flank back to the first objective.

To the north of 9th Division the 55th Division began the day understrength, after the losses of 31 July. Replacements had arrived slowly and 1,000 soldiers were left out of the battle having arrived too late to be trained for the attack. German artillery and machine-gun fire from Reserve Regiment 91 of the 2nd Guards Reserve Division hit the infantry with intense fire as the attack began. The mist worked to the Germans' advantage in this part of the front, because the depleted British units missed several German strong points and dug-outs, from which the Germans were able to stop the British support waves from moving up. The advanced troops realising this either halted or turned back and lost the barrage. The difficulties of the division were made worse at 7:08 a.m. when the scheduled advance to the final objective coincided with the dispersal of the mist. Reserves were pushed forward around 10:00 a.m. from 166th Brigade, which allowed the 165th and 164th Brigades to take the first objective around Gallipoli Farm and the Schuler Galleries in front of Schuler Farm by mid-day. Fighting at Hill 35 continued and the Germans regained Hill 37 with a counter-attack. Machine-guns were placed in the Schuler Galleries and nine were dug in near Keir Farm, which were able to stop German counter-attacks from making any more progress. In the afternoon the rest of the reserve brigade was able to capture Hills 35 and 37, which dominated the Zonnebeke spur. The right of the division established touch with the 9th Division but the centre and left of 55th Division were 500 yd short of the final objective.

XVIII Corps was to advance onto the Gravenstafel and Poelcappelle spurs, held by the German 36th Division since 8 September. The divisions had to assemble east of the Steenbeek between St Julien and Langemarck in low ground which was still muddy and full of flooded shell-holes despite the better weather. The 58th Division objective was 1000 yd ahead, among German strong points on the west end of Gravenstafel spur. As a frontal attack here had failed, the division feinted with its right brigade, while the left brigade made the real attack from the flank. The feint captured Winnipeg cross-roads, as the main attack by three battalions one behind the other, captured Vancouver Farm, Keerselaere and Hubner Farm. The next two battalions passed through and turned right half way up the spur, to reach Wurst Farm on a tactically vital part of the spur at the same time as the barrage. Nearly 300 prisoners and fifty machine-guns were taken and outposts were established to the left overlooking the Stroombeek valley. The division ascribed the success to the excellence of their training, an excellent creeping barrage and smoke shell, which had thickened the mist and blinded the German defenders and that gas shell barrages on the German reinforcement routes had depressed German morale.

51st Division further north, had the same task on Poelcappelle spur. The division advanced with one brigade on a 1400 yd front. The Germans in the Wilhelm (third) Line were ready for them and fought until they were almost annihilated in new machine-gun nests that they had dug in front of their front line, which had avoided the worst of the artillery bombardment. The division was able to reach the final objective in sight of Poelcappelle village. By these advances XVIII Corps got observation of Poelcappelle and up the Lekkerboterbeek and Lauterbeek valleys, the capture of which allowed British artillery to move forward of the Steenbeek.

20th Division on the right of XIV Corps, had to form the northern defensive flank of the offensive, on a front of 1400 yd from Poelcappelle spur to the Ypres – Staden railway. Two brigades attacked with two battalions each. The German Wilhelm (third) Line, here known as Eagle trench, was held as determinedly as that part in the 51st Division sector ("Pheasant trench") despite a bombardment from Livens Projectors (which fell behind the German trench and illuminated the British infantry as they advanced). By the end of the day the division was still short of the first objective, except on the left next to the railway.

The British offensive had captured most of the German outpost zones to a depth of about 1500 yd. As the ground was captured it was prepared for defence, in anticipation of counter-attacks by the German Eingreif divisions. Captured German machine-gun nests and strong points were garrisoned and wired with German barbed wire found in the area. The final objective became the outpost zone and the second objective the main line of resistance, a chain of irregular posts using shell-holes concealed by folds of the ground and reverse slopes, avoiding trenches which attracted German shell fire. Communication between the infantry and artillery was established with runners, messenger dogs and pigeons. Wireless transmitters and power buzzers were set up at brigade headquarters and artillery observation posts, one for each artillery group. Engineer and pioneer units began to dig in telephone lines, which took until the afternoon of 21 September.

Air operations
Observing and reporting on German counter-attack movements was made a duty for all aircraft and patrol areas were given to II and V Brigades and the Ninth Wing to observe. "Hostile Tactical Maps" were issued, showing German assembly points and the likely routes to them and towards the front line. II Brigade covered the Second Army front east to the Roulers–Menin railway. The area was divided into three sectors, each with a counter-attack patrol of two fighters, maintained for eight hours after "zero-hour", flying below 500 ft and using the special maps, to attack any German units they caught on the move and to drive off German low-flying aircraft. On return they were to telephone a report direct to the Second Army Report Centre at Locre, similar arrangements being made for the Fifth Army. Ninth Wing aircraft were to patrol at low altitude east of Zarren–Oostnieukerke–Menin, beginning two hours after the start of the attack, to harass German reinforcements. Corps squadrons were to maintain counter-attack patrols on their Corps fronts, calling for immediate artillery fire and warning British infantry by smoke signal. Not all of these measures were possible on the day due to the weather, because it had rained on 19 September and was misty next morning but air operations commenced as soon as the mist cleared at 8.00 a.m. German aircraft attempting to intervene during the battle suffered from the presence of anti-aircraft guns near the front line and a Lewis gunner of a pioneer battalion in the 19th Division, shot down a German aircraft in flames at 1:30 p.m.; the feat was repeated next day and several German formations were broken up by ground fire.

German Fourth Army counter-attacks
During the British infantry advances, German artillery managed a considerable amount of counter-battery fire, particularly from Zillebeke to Vebrandenmolen but this was not enough to stop the British artillery heavily bombarding German reserve battalions of the ground-holding (Stellungsdivisionen) divisions as they made futile attempts to counter-attack between 10:00 a.m. and 1.30 p.m. At 1:48 p.m. the British standing barrage in front of the new line ended. Air reconnaissance from zero hour by a contact aeroplane over each Corps area, to observe the progress of the British infantry and one counter-attack observation machine watching for German counter-attacks, revealed German Eingreif units advancing from Flandern III at Menin, Moorslede and Westroosebeek. During the day 394 wireless messages were received from British observation aircraft, about a third resulting in immediate artillery fire.

After 3.00 p.m. approximately three German infantry battalions were reported north of the Menin Road moving up the Reutelbeek valley towards Polderhoek, a similar force with field artillery was seen moving west towards I Anzac Corps at Polygon Wood and Anzac spur and another was observed, descending from the Poelcappelle spur at Westroosebeek towards positions held by the Fifth Army. These troops were the leading regiments of three Eingreif divisions, 16th Bavarian from Gheluwe, 236th Division from Moorslede and 234th Division from Oostniewkirke. The 16th Bavarian Division counter-attack plan "Get Closer" (Näher heran) had been ordered at 5:15 a.m. By 9:00 a.m. the division advanced towards the area between Polygon Wood and Inverness Copse. British medium and heavy artillery fired on the German units, which were forced to deploy and advance from cover. After considerable delay the survivors reached British machine-gun range as their artillery support overshot the British positions. Visibility was still exceptionally good, with the sun behind the British who were easily able to see all movement in front of them on the Gheluvelt plateau. The German force moving up the Reutelbeek valley into the area of 23rd and 1st Australian divisions was watched by the infantry for an hour, when at 7:02 p.m. a field artillery and machine-gun barrage fell on the Germans for an hour, stopping all movement towards the British positions, "16th Bavarian Division was a high quality formation, but all the skill and dash in the world stood no chance in the face of the torrent of fire the British artillery could bring to bear at the critical points".

A similar barrage for forty minutes in front of 2nd Australian division on a regiment of the 236th Division advancing from Molenaarelsthoek and downhill from Broodseinde, stopped the counter-attack long before it came within range of the Australian infantry. On the southern edge of the plateau, German troops dribbling forward in the 39th Division area managed to reinforce the garrison at Tower Hamlets, then tried twice to advance to the Bassevillebeek and were "smashed" by artillery and machine-gun fire.

In the Fifth Army area, from 800 yd south of the Ypres – Roulers railway, north to the Ypres – Staden railway, many Germans were seen moving west down Passchendaele ridge around 5:30 p.m. into the area held by the 55th, 58th and 51st divisions. In the 58th Division area fire was opened on the Germans after half an hour, which forced the Germans to deploy into open order. When the Germans were 150 yd from the first British strong point, the British defensive barrage arrived with such force that the German infantry "stampeded". No Germans were seen in the area until night when patrols occupied an outpost. On the 55th Division front "an extraordinarily gallant" German counter-attack by the 459th Reserve Regiment (236th Division) from Gravenstafel, on Hill 37 through Reserve Regiment 91, was stopped by artillery and enfilade fire by machine-guns at Keir Farm and Schuler Galleries. A German attack down Poelcappelle spur at 5:30 p.m. towards the 51st Division had much better artillery support and although stopped in the area of the Lekkerboterbeek by 7:00 p.m., pushed the British left back to Pheasant trench (Wilhelm Line) before the British counter-attacked, pushing the Germans back to the line of the first objective, 600 yd short of the final objective. By nightfall the German Eingreif divisions had been defeated. The British Official History records that the counter-attack divisions had been held back, waiting for another British advance.

Casualties
British casualties 20–25 September are given by the British Official Historian as 20,255; 3,148 being killed, the 19th Division lost 1,933 casualties. 3,243 prisoners were taken with "very heavy" losses of killed or wounded inflicted on the German defenders. The Official Historian's calculations of German losses have been severely criticised ever since.

Subsequent operations
Minor attacks took place after 20 September as both sides jockeyed for position and reorganised their defences. In the Second Army area on 21 September, a 41st Division brigade attacked towards Bassevillbeek Copse, through extremely boggy ground by short rushes and consolidated posts on the Bassevillebeek. Several German counter-attacks in the afternoon were repulsed and at 7:00 p.m. a much larger German attack was dispersed by artillery and small-arms fire. In the evening a German attack was made on Hill 37 against the 55th Division, taking some ground behind a heavy barrage, until a British counter-attack restored the position by 9:15 p.m. A German raid on posts of the 8th Division (II Corps) next day failed and in the X Corps area the 23rd Division and the 1st Australian Division (I Anzac Corps) re-took the front line. In the XVIII Corps area the 58th Division held Stroppe Farm and in the evening the 51st Division repulsed a big German attack from Poelcappelle with artillery and small-arms fire. The 20th Division repulsed a German attack at 6.30 a.m., then attacked Eagle Trench from both ends and captured it, despite fierce German resistance. Crown Prince Rupprecht wrote in his diary for 23 and 24 September that the Germans could not allow the British to remain in control of the higher ground around Zonnebeke or the Gheluvelt Plateau and that counter-strokes during the next enemy attack must reach their objectives. The Fourth Army lacked reserves and needed time to meet another attack.

A bigger German attack on 25 September, on a 1800 yd front, from the Menin Road to Polygon Wood, began as the 23rd Division was being relieved by the 33rd Division. A German bombardment from 20 heavy and 44 field batteries (nearly four times the usual amount for a German division) began at 5:15 a.m., part of which fell short onto the German infantry of two 50th Reserve Division regiments, which fell back until the bombardment began its creep towards the British positions. The German infantry advanced in the morning mist, either side of the Reutelbeek as the artillery boxed the British position opposite, which isolated it from its supports and prevented supplies of ammunition from being brought to the front line. The German attack made little progress on the British right, lost direction in the gloom and veered north, joined with the German battalion there and reached Black Watch Corner, at the south-western extremity of Polygon Wood, which was lost during the Battle of Polygon Wood next day.