Battle of Passchendaele

The Battle of Passchendaele (or Third Battle of Ypres or "Passchendaele") was a campaign of the First World War, fought by the British and their allies against the German Empire. The battle took place on the Western Front, between July and November 1917, for control of the ridges south and east of the Belgian city of Ypres in West Flanders, as part of a strategy decided by the Allies at conferences in November 1916 and May 1917. Passchendaele lay on the last ridge east of Ypres, five miles from a railway junction at Roeselare, which was a vital part of the supply system of the German Fourth Army. The next stage of the Allied strategy was an advance to Torhout–Couckelaere, to close the German-controlled railway running through Roeselare and Torhout, which did not take place until 1918. Further operations and a British supporting attack along the Belgian coast from Nieuwpoort, combined with an amphibious landing, were to have reached Bruges and then the Dutch frontier. The resistance of the German Fourth Army, unusually wet weather, the onset of winter and the diversion of British and French resources to Italy, following the Austro-German victory at the Battle of Caporetto (24 October – 19 November) allowed the Germans to avoid a general withdrawal, which had seemed inevitable to them in October. The campaign ended in November when the Canadian Corps captured Passchendaele. In 1918 the Battle of the Lys and the Fifth Battle of Ypres, were fought before the Allies occupied the Belgian coast and reached the Dutch frontier.

A campaign in Flanders was controversial in 1917 and has remained so. British Prime Minister Lloyd George opposed the offensive as did General Foch the French Chief of the General Staff. The British commander Field Marshal Sir Douglas Haig did not receive approval for the Flanders operation from the War Cabinet until 25 July. Matters of dispute by the participants and writers and historians since the war have included the wisdom of pursuing an offensive strategy in the wake of the failed Nivelle Offensive, rather than waiting for the arrival of the American armies in France; the choice of Flanders over areas further south or the Italian front; the climate and weather in Flanders; Haig's selection of General Hubert Gough and the Fifth Army to conduct the offensive; debates over the nature of the opening attack between advocates of shallow and deeper objectives; the passage of time between the Battle of Messines and the opening attack of the Battles of Ypres; the extent to which the internal troubles of the French armies motivated British persistence in the offensive; the effect of mud on operations; the decision to continue the offensive in October once the weather had broken and the human cost of the campaign on the soldiers of the German and British armies.

Flanders 1914–1917
The Treaty of London (1839) recognized Belgium as an independent and neutral state. The German invasion of Belgium on 4 August 1914, in violation of Article VII of the treaty, was the reason given by the British government for declaring war. British military operations in Belgium began with the arrival of the British Expeditionary Force (BEF) at Mons on 22 August. On 16 October the Belgians, with some French reinforcements, began the defence of the French channel ports and what remained of unoccupied Belgium at the Battle of the Yser. Operations further south in Flanders commenced, after attempts by the French and German armies to turn their opponents' northern flank through Picardy, Artois and Flanders, (the 'Race to the Sea') reached Ypres. On 10 October, Lieutenant-General Erich von Falkenhayn, Chief of the General Staff ordered an attack towards Dunkirk and Calais followed by a turn south to gain a decisive victory. When the offensive failed, Falkenhayn ordered the capture of Ypres to gain a local advantage. By 12 November, the First Battle of Ypres had failed (at a cost of 160,000 German casualties), and was stopped on 18 November.

In December 1914, the Admiralty began discussions with the War Office for a combined operation to occupy the Belgian coast to the Dutch frontier, by an attack along the coast combined with a landing at Ostend. Eventually the British were obliged to participate in the French offensives further south. Thus large British offensive operations in Flanders were not possible in 1915, due to the consequent lack of resources. The Germans conducted their own Flanders offensive at the Ypres (22 April – 15 May 1915), making the Ypres salient more costly to defend. Sir Douglas Haig succeeded Sir John French as Commander-in-Chief of the BEF on 19 December 1915. A week after his appointment Haig met Vice-Admiral Sir Reginald Bacon, who emphasised the importance of obtaining control of the Belgian coast, to end the threat from there by German naval forces. Haig was sceptical of a coast operation, believing that a landing from the sea would be far more difficult than anticipated and that an advance along the coast would require so much preparation that the Germans would have ample warning. Haig preferred an advance from Ypres, to bypass the flooded area around the Yser and the coast, before a coastal attack was attempted, to clear the coast to the Dutch border.

In January 1916, Haig ordered General Plumer to plan offensives against Messines Ridge, Lille and Houthoulst Forest. General Rawlinson was also ordered to plan an attack from the Ypres Salient on 4 February. Planning by Plumer continued but the demands of the Battles of Verdun and the Somme absorbed the offensive capacity of the British Expeditionary Force. On 15 and 29 November 1916, as the Battle of the Somme paused, Haig met Général d'Armée Joffre and the other Allies at Chantilly. An offensive strategy to overwhelm the Central Powers was agreed, with attacks planned on the Western, Eastern and Italian Fronts, by the first fortnight in February 1917. A meeting in London of the Admiralty and General Staff urged that the Flanders operation be undertaken in 1917, and Joffre replied on 8 December agreeing to the proposal for a Flanders campaign after the spring offensive. The plan for a year of steady attrition on the Western Front, with the main effort in the summer being made by the British Expeditionary Force, was scrapped by Nivelle and the French government for a decisive battle, to be conducted in February by the French army, with the British army's contribution becoming a preliminary operation, the Battles of Arras.

Nivelle planned an operation in three parts, preliminary offensives to pin German reserves by the British at Arras and the French between the Somme and the Oise, a French breakthrough offensive on the Aisne, then pursuit and exploitation. The plan was welcomed by Haig with reservations, which he addressed on 6 January. After repeated insistence on Haig's part, Nivelle agreed to a proviso that if the first two parts of the operation failed to lead to part three, they would be stopped so that the British could move their main forces north for the Flanders offensive, which Haig argued was of great importance to the British government. Haig wrote on 23 January that it would take six weeks to move British troops and equipment from the Arras front to Flanders and on 14 March he noted that the attack on Messines Ridge could be made in May. On 21 March he wrote to Nivelle that it would take two months to prepare the attacks from Messines to Steenstraat but that the Messines attack could be ready in 5–6 weeks. On 16 May Haig wrote that he had divided the Flanders operation into two phases, one to take Messines Ridge and the main attack several weeks later. British determination to clear the Belgian coast took on more urgency after the Germans resumed unrestricted submarine warfare on 1 February 1917.

Small operations took place in the Ypres salient in 1916, some being German initiatives to distract the Allies from the preparations for the offensive at Verdun and later to try to divert Allied attention from the Battle of the Somme. Other operations were begun by the British, to regain territory or to evict the Germans from ground overlooking their positions. Engagements took place on 12 February at Boesinge and on 14 February at Hooge and Sanctuary Wood. There were actions on 14–15 February and 1–4 March at The Bluff, 27 March – 16 April at the St Eloi Craters and the battle of Mount Sorrel 2–13 June.

In January 1917, the Second Army (II Anzac, IX, X and VIII corps) held the line in Flanders from Laventie to Boesinghe, with 11 divisions and up to two in reserve. There was much trench mortaring, mining and raiding by both sides, and from January to May the Second Army had 20,000 casualties. In May, reinforcements began moving to Flanders from the south, II Corps and 17 divisions had arrived by the end of the month.

Strategic background
Several British and French operations took place beyond Flanders during the 3rd Ypres campaign, intended to assist Allied operations at Ypres, by obstructing the flow of munitions and reinforcements to the German Fourth Army in Belgium and to exploit opportunities created by the German need to economise elsewhere. German offensives in Russia and against Italy were postponed several times as the demand for men and munitions in Flanders left little available for other operations and the French army was able to continue its recuperation after the Nivelle Offensive.

Geography and climate
The front line around Ypres had changed relatively little since the end of the Second Battle of Ypres (22 April – 25 May 1915). The British held the city, while the Germans held the high ground of the Messines–Wytschaete ridge to the south, the lower ridges to the east and the flat ground to the north. The Ypres front was a salient bulging into German positions, overlooked by German artillery on the higher ground. It was difficult for the British forces to gain ground observation of the German rear areas east of the ridges.

In Flanders, sands, gravels and marls predominate, in places covered by silts. The coastal strip is sand but a short way inland, the ground rises to the vale of Ypres, which before 1914 was a flourishing market garden. Ypres is 20 m above sea level; Bixshoote 4 mi to the north is at 8.5 m. To the east the land is at 20 – for several miles, with the Steenbeek river at 15 m near St Julien. There is a low ridge from Messines, 80 m at its highest point, running north-east past "Clapham Junction" at the west end of Gheluvelt plateau (2½ miles from Ypres at 65 m and Gheluvelt (above 50 m) to Passchendaele, (5½ miles from Ypres at 50 m) declining from there to a plain further north. Gradients vary from negligible, to 1 in 60 at Hooge and 1 in 33 at Zonnebeke.

Underneath the soil is London clay, sand and silt; according to the Commonwealth War Graves Commission categories of sand, sandy soils and well-balanced soils, Messines ridge is "well-balanced soil" and the ground around Ypres is "sandy soil". The ground is drained by many streams, canals and ditches which need regular maintenance. Since 1914 much of the drainage had been destroyed, although some parts had been restored by Land Drainage Companies brought from England. The area was considered by the British to be drier than Loos, Givenchy and Plugstreet Wood further south. A 1989 study of weather data recorded at Lille, 16 mi from Ypres between 1867 and 1916, showed that August was more often dry than wet, that there was a trend towards dry autumns (September – November) and that average rainfall in October had decreased over the previous 50 years.

British plans for a Flanders campaign
Preparations for operations in Flanders began in 1915, with the doubling of the Hazebrouck–Ypres rail line and the building of a new line Bergues–Proven which was doubled in early 1917. Progress on roads, rail lines, railheads and spurs in the Second Army zone was continuous and by mid-1917 gave the area the most efficient supply system of the British Expeditionary Force in France. Several plans and memoranda for a Flanders offensive were produced between January 1916 and May 1917, in which the writers tried to relate the offensive resources available to the terrain and the likely German defence. In early 1916 the importance of the capture of the Gheluvelt plateau for an advance further north was emphasised by Haig and the army commanders.

On 14 February 1917 Colonel Macmullen of the GHQ staff, proposed that the plateau be taken by a mass tank attack, reducing the need for artillery; in April a reconnaissance by Captain G. le Q Martel found that the area was unsuitable for tanks. On 9 February General Rawlinson, commander of the Fourth Army suggested that Messines Ridge could be taken in one day and that the capture of the Gheluvelt plateau should be fundamental to the attack further north. He suggested that the southern attack from St Yves to Mount Sorrel should be first and that Mount Sorrel to Steenstraat be attacked within 48–72 hours. After discussions with Rawlinson and Plumer and the incorporation of Haig's changes, Macmullen submitted his memorandum on 14 February. With amendments the memorandum became the GHQ 1917 plan.

On 1 May 1917, Haig wrote that the Nivelle Offensive had weakened the German army but that a decisive blow would be premature. An offensive at Ypres would continue the wearing-out process, on a front where the Germans could not refuse to fight. Even a partial success would improve the tactical situation in the Ypres salient, reducing the exceptional "wastage" which occurred even in quiet periods. In early May Haig set the timetable for his Flanders offensive, with 7 June the date for the preliminary attack on Messines Ridge. A week after the Battle of Messines Ridge, Haig gave his objectives to his Army commanders: wearing out the enemy, securing the Belgian coast and connecting with the Dutch frontier by the capture of Passchendaele ridge, followed by an advance on Roulers and Operation Hush, an attack along the coast with an amphibious landing. If manpower and artillery were insufficient, only the first part of the plan might be fulfilled. On 30 April, Haig told Gough the Fifth Army commander, that he would lead the "Northern Operation" and the coastal force, although Cabinet approval for the offensive was not granted until 21 June.

German defences in Flanders
The Fourth Army had 25 mi of front to defend with three "Groups", (corps headquarters and a varying complement of divisions) Dixmude (XIV Corps), Ypres (III Bavarian Corps) and Wytschaete (IX Reserve Corps); Group Staden (Guards Reserve Corps) was added later. Group Dixmude held 12 mi with four front divisions and two Eingreif divisions; Group Ypres held 6 mi from Pilckem to Menin Road with three front divisions and two Eingreif divisions and Group Wijtschate held a similar length of front south of Menin Road with three front divisions and three Eingreif divisions. The Eingreif divisions were placed behind the Menin and Passchendaele ridges. 5 mi further back were four more Eingreif divisions and 7 mi beyond them another two in Oberste Heeresleitung reserve.

German anxiety that the British would exploit their victory at Messines by advancing to the Bassevillebeek (Tower Hamlets) spur beyond the north end of Messines ridge, led Crown Prince Rupprecht on 9 June to propose a withdrawal to the Flandern line in the area east of Messines; construction of defences in the area began but on 13 June Colonel von Lossberg arrived as the new Chief of Staff of Fourth Army. Lossberg rejected the proposed withdrawal to the Flandern line and ordered that the current front line east of the Sehnen line ("Oosttaverne" Line to the British) be held rigidly, as the front of a deepened Flandern Stellung (position), in front of the Flandern line which was to become Flandern I, with a new Flandern II line built west of Menin, north to Terhand and Passchendaele, at the back of a new Flandern II Stellung. Construction of Flandern III was begun east of Menin north to Moorslede.

On 25 June Ludendorff suggested to Rupprecht that Group Ypres should withdraw to the Wilhelm (third) line, leaving only outposts in the Albrecht (second) line. On 30 June Rupprecht's Chief of Staff, General von Kuhl suggested a withdrawal to Flandern I along Passchendaele ridge, meeting the old front line in the north near Langemarck and close to Armentieres in the south. Such a withdrawal would avoid a hasty retreat from Pilckem ridge and also force the British into a time-consuming redeployment. Lossberg disagreed, believing that the British would launch a broad front offensive, that the ground east of the Sehnen line was easy to defend, that the Menin road ridge could be held if it was made the schwerpunkt (point of main effort) of the German defensive system and that Pilckem ridge deprived the British of ground observation over the Steenbeek Valley, while the Germans could see the area from Passchendaele Ridge, allowing German infantry to be supported by observed artillery fire. Lossberg's judgement was accepted and no withdrawal was made.

Messines Ridge: 7–17 June
The first stage in the British plan was a preparatory attack on the German positions south of Ypres at Messines ridge. These German positions dominated Ypres and unless neutralised, would be able to enfilade any British attack eastwards from the salient. The British advance began on 7 June and was preceded by a unique display of military pyrotechnics. Since mid-1915, the British had been covertly digging mines under the German positions on the Messines Ridge. By June 1917 21 mines had been dug, filled with nearly 1000000 lb of explosives. The Germans knew the British were mining and had taken some countermeasures but they were surprised by the extent of the mining. Two of the British mines failed to detonate but the remaining 19 were fired on 7 June at 3:10 a.m. British Summer Time. The final objectives were largely gained before dark. British losses in the morning were light, although the plan had expected casualties of up to 50% in the initial attack. As the infantry advanced over the back edge of the ridge, giving targets to German artillery and machine-guns, British artillery was less able to provide covering fire. Fighting continued on the lower slopes, on the east side of the ridge until 14 June. The attack prepared the way for the main attack later in the summer, by removing the Germans from the dominating ground on the southern face of the Ypres salient, that they had held for two years.

Kerensky offensive
The Russian army launched the Kerensky Offensive in an attempt to honour the agreement struck with its allies at the Chantilly meeting of 15–16 November 1916. After the brief success of the Kerensky Offensive 1–19 July and its disastrous sequel, when Ludendorff's general reserve of six divisions captured Riga, 1–5 September 1917 and then in Operation Albion September–October 1917 took the islands at the mouth of the Gulf of Riga, British and French commanders on the Western Front had to reckon on the German western army being strengthened by reinforcements from the Eastern Front in late 1917. Haig wished to exploit the diversion of German forces in Russia for as long as it continued and urged that the maximum amount of manpower and munitions be committed to the battle in Flanders.

First phase, Gough's command: May–August


Haig selected Gough to command the offensive on 30 April and on 10 June Gough took over the Ypres salient north of Messines Ridge. Gough planned an offensive based on the GHQ 1917 plan and the instructions he had received from Sir Douglas Haig. On the understanding that Haig wanted a more ambitious version, Gough held meetings with his Corps commanders on 6 and 16 June where the third objective, which included the German Wilhelm (third) line, was added to the first and second objectives due to be taken on the first day. A fourth objective was also given for the first day but was only to be attempted opportunistically, in places where the German defence had collapsed. An attack of this nature was not a breakthrough operation; the German defensive position Flandern I lay 10000 – behind the front line and would not be attacked on the first day, nonetheless it was more ambitious than Plumer's earlier plan, which had involved an advance of 1000 –. Major-General J. Davidson, Director of Operations at GHQ wrote in a memorandum that there was "ambiguity as to what was meant by a step-by-step attack with limited objectives" and suggested reverting to a 1750 yd advance to increase the concentration of British artillery. Gough's reply stressed the need to plan for opportunities to take ground left temporarily undefended and that this was more likely in the first attack which would have the benefit of long preparation. After discussions at the end of June, Haig endorsed Gough's plan, as did Plumer the Second Army commander.

Battle of Pilckem Ridge: 31 July – 2 August
The British attack began at 3:50 a.m. on 31 July. The attack was meant to commence at dawn but low cloud meant that it was still dark. The main attack of the offensive by II Corps across the Ghelveult Plateau to the south, confronted the principal German defensive concentration of artillery, ground-holding and Eingreif divisions. The attack had most success on the left (north), in front of XIV Corps and the French First Army. In this section of the front, the Entente forces advanced 2500 –, up to the line of the Steenbeek stream. In the centre of the British attack, XVIII Corps and XIX Corps pushed forward to the line of the Steenbeek to consolidate and sent reserve troops towards the Green and Red lines, (on XIX Corps's front) an advance of some 4000 yd. Group Ypres counter-attacked the flanks of the British break-in, supported by all available artillery and aircraft at about midday. The German counter-attack was able to drive the British back to the 'black line' with 70% losses, then the German counter-attack was stopped by mud, artillery and machine-gun fire.

Capture of Westhoek: 10 August
II Corps attacked on 10 August to capture the rest of the black line on the Gheluvelt plateau not held on 31 July. The advance succeeded but German artillery fire and infantry counter-attacks isolated the British infantry of 18th Division, which had captured Glencorse Wood. At about 7:00 p.m., German infantry attacked behind a smokescreen and recaptured all but the north-west corner of the wood, only 25th Division's gains on Westhoek Ridge being held. Albrecht von Thaer, Staff Officer at Group Wytshchate noted that casualties after 14 days in the line averaged 1,500–2,000 men compared to the Somme 1916 average of 4,000 men and that German troop morale was higher than in 1916.

Battle of Hill 70
The Battle of Hill 70 was a subsidiary operation between the Canadian Corps and five divisions of the German Sixth Army. The battle took place on the outskirts of Lens in the Nord-Pas-de-Calais region of France, from 15–25 August. General Von Kuhl wrote later that it was a costly defeat and "wrecked" the plan for relieving divisions which had been "fought-out" in Flanders.

Battle of Langemarck: 16–18 August
Fifth Army headquarters was influenced by the effect that delay would have on the coastal operation, which needed the high tides at the end of August or it would have to be postponed for a month. Gough intended the rest of the green line (just beyond the German Wilhelm (third) line from Polygon Wood to Langemarck) to be taken and the Steenbeek crossed further north. In the II Corps area the disappointment of 10 August was repeated, with the infantry managing to advance, being isolated by German artillery and then (except in the 25th Division area near Westhoek) forced back to their start line by German infantry counter-attacks. Attempts by the German infantry to advance further were stopped by British artillery fire with heavy losses. The advance further north in the XVIII Corps area retook and held the north end of St Julien and the area south-east of Langemarck, while XIV Corps captured Langemarck and the Wilhelm (third) line north of the Ypres–Staden railway near the Kortebeek. The French First Army conformed, pushing up to the Kortebeek and St Jansbeck stream west of the northern stretch of the Wilhelm (third) line, where it crossed to the east side of the Kortebeek.

Subsidiary operations: 19–27 August
Most of the smaller attacks failed to hold ground, although a XVIII Corps attack on 19 August succeeded. Exploiting observation from higher ground to the east, the Germans were able to inflict heavy losses on the British divisions holding the new line beyond Langemarck. After two fine dry days from 17–18 August, XIX and XVIII Corps began pushing closer to the Wilhelm (third) line. On 20 August an operation by British tanks, artillery and infantry captured strong points along the St Julien–Poelkappelle road and two days later more ground was gained by XVIII and XIX Corps, which left them still overlooked by the Germans in the un-captured part of the Wilhelm (third) line. II Corps resumed operations to capture Nonne Bosschen, Glencorse Wood and Inverness Copse around the Menin Road on 22–24 August, which failed with many losses on both sides.

Gough laid down a new infantry formation of skirmish lines followed by "worms" on 24 August. Cavan noted that pill-box defences required broad front attacks so as to engage them simultaneously. The British general offensive intended for 25 August was delayed because of the failure of previous attacks to hold ground, following the Battle of Langemarck and then postponed due to more bad weather. Attacks on 27 August were minor operations which were costly and inconclusive. Haig called a halt to these operations amidst tempestuous weather.

Second offensive battle of Verdun
Petain had committed the French Second Army to an attack at Verdun in mid-July in support of the operations in Flanders. The Second Offensive Battle of Verdun was delayed, partly due to the mutinies which had affected the French army after the failure of the Nivelle Offensive and also because a German attack at Verdun from 28–29 June, captured part of the ground intended as a jumping-off point for the French attack. A French counter-attack on 17 July captured the ground, then the Germans regained it on 1 August, then took ground on the east bank on 16 August. The Second Offensive Battle of Verdun finally began on 20 August and by 9 September had taken 10,000 prisoners. Fighting continued sporadically into October, adding to the German army's difficulties on the Western Front and elsewhere. Ludendorff wrote,

"On the left bank, close to the Meuse, one division had failed ... and yet both here and in Flanders everything possible had been done to avoid failure ... The French army was once more capable of the offensive. It had quickly overcome its depression." (Ludendorff, memoirs)."

there was no counter-attack, as the local Eingreif divisions were in Flanders.

Second phase, Plumer takes over: 25 August – 10 November
The German Fourth Army had defeated the British advance to all of the objectives of 31 July during August but the high casualties and sickness caused by the ground conditions, endless bombardments and air attacks intensified the manpower shortage, that the German defensive strategy for 1917 was intended to alleviate. Haig transferred authority for the offensive to General Plumer, the Second Army commander on 25 August and moved the northern boundary of the Second Army closer to the Ypres–Roulers railway. More heavy artillery was sent to Flanders from the armies further south and placed opposite the Gheluvelt plateau.

Plumer's plans continued the development of British attacking methods, which had also taken place in the Fifth Army, during the slow progress in August against the German defence-in-depth and the unusually wet weather. After a pause of about three weeks, Plumer intended to capture Gheluvelt plateau in four steps, with six days between each step to allow time to bring forward artillery and supplies. Each attack was to have limited geographical objectives like the attacks in August, with infantry brigades re-organised to attack the first objective with one battalion each and the final one with two battalions. Plumer arranged for much more medium and heavy artillery to be added to the creeping bombardment, which had been impossible with the amount of artillery available to Gough. The revised attack organisation was intended to have more infantry attacking on narrower fronts, to a shallower depth than the attack of 31 July. The quicker and shorter advances were intended to be consolidated on tactically advantageous ground (particularly on reverse slopes) with the infantry in contact with their artillery and air support, before they received counter-attacks. The tempo of these operations was intended to add to German difficulties, in replacing tired divisions through the transport bottlenecks behind the German front.

The pause in British operations while Plumer moved even more artillery into the area of the Gheluvelt plateau helped to mislead the Germans. Albrecht von Thaer, Staff Officer at Group Wijtschate wrote that it was "almost boring". At first 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 Von Kuhl's 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 Fourth Army.

German defensive changes
Instead of being one to two miles distant, as on 31 July, on 20 September the British objectives were approximately 1500 yd away, without the disadvantage of rain soaked ground and poor visibility encountered in August. The advances were much quicker and the final objective was reached a few hours after dawn, which confounded the German counter-attack divisions. Having crossed two miles of mud, the Eingreif divisions found the British already established along a new defence line, with the forward battle zone and its weak garrison gone beyond recapture. After the Battle of Menin Road the German defensive system was changed, beginning a search for expedients, which lasted for the rest of the battle. In August German front-line divisions had two regiments of three battalions deployed forward, with the third regiment in reserve. The front battalions had needed to be relieved much more frequently than expected, due to the power of British attacks, constant artillery fire and the weather, which caused units to become mixed up. The reserve regiments had not been able to intervene early enough, leaving the front battalions unsupported, until the Eingreif divisions arrived, some hours after the commencement of the attack.

After another severe defeat on 26 September, the German commanders made more changes to the defensive deployment of their troops and altered their counter-attack tactics, which had been negated by Plumer's more conservative form of limited attacks. In July and August, German counter-attack (Eingreif) divisions had engaged in a manner analogous to an advance to contact during mobile operations which had given the Germans several costly defensive successes. The counter-attacks in September had been assaults on reinforced field positions, due to the restrained nature of British infantry advances. The fine weather in early September had greatly eased British supply difficulties, especially in the delivery of huge amounts of artillery ammunition. Immediately after their attacks, the British had made time to establish a defence in depth, behind standing barrages, in dry clear weather, with increased air support over the battlefield for counter-attack reconnaissance, contact patrols and ground-attack operations. Systematic defensive artillery support was forfeited by the Germans, due to uncertainty over the position of their infantry, just when the British infantry benefitted from the opposite. German counter-attacks were defeated with heavy casualties and on 28 September Albrecht von Thaer, Staff Officer at Group Wytschaete wrote that the experience was "awful" and that he did not know what to do.

Ludendorff ordered a strengthening of forward garrisons by the ground-holding divisions. All available machine-guns, including those of the support and reserve battalions of the front line regiments, were sent into the forward zone to form a cordon of four to eight guns every 250 yd. The ground holding divisions were reinforced by the Stoss regiment of the Eingreif division being moved up behind each front division, into the artillery protective line behind the forward battle zone, to launch earlier counter-attacks while the British were consolidating. The bulk of the Eingreif divisions were to be held back and used for a methodical counter-stroke on the next day or the one after and for counter-attacks and spoiling attacks between British offensives. Further changes of the Fourth Army's defensive methods were ordered on 30 September. Operations to increase British infantry losses in line with the instructions of 22 September were to continue. Gas bombardment of forward British infantry positions and artillery emplacements, was to be increased whenever the winds allowed. Every effort was to be made to induce the British to reinforce their forward positions, where the German artillery could engage them. Between 26 September and 3 October the Germans attacked at least 24 times. Operation Hohensturm, a bigger German methodical counter-attack, intended to recapture the area around Zonnebeke was planned for 4 October.

Battle of the Menin Road Ridge: 20–25 September
The plan included more emphasis on the use of heavy and medium artillery, to destroy German concrete pill-boxes and machine-gun nests, which were more numerous in the battle zones being attacked and to engage in more counter-battery fire. The British had 575 heavy and medium and 720 field guns and howitzers, more than doubled the proportion available at the Battle of Pilckem Ridge. 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.

On 20 September the Allies attacked on a 14500 yd front and captured most their objectives to a depth of about 1500 yd by mid-morning. The Germans made many counter-attacks, beginning around 3.00 p.m. until early evening, all of which failed to gain ground or made only a temporary penetration of the new British positions on the Second Army front. The attack was a great success and showed that the German defences could no longer stop well-prepared attacks made in good weather. Minor attacks took place after 20 September as both sides jockeyed for position and reorganised their defences. A larger attack by the Germans on 25 September recaptured pillboxes at the south western end of Polygon Wood at the cost of heavy casualties. Not long after, the German positions near Polygon Wood were swept away by Plumer's attack of 26 September (the Battle of Polygon Wood).

Battle of Polygon Wood: 26 September – 3 October


The Second Army altered its Corps frontages soon after the attack of 20 September, so that each attacking division could be concentrated on a 1000 yd front. Roads and light railways were extended to the new front line to allow artillery and ammunition to be moved forward. Artillery from VIII and IX Corps in the south acted to threaten attacks on Zandvoorde and Warneton. At 5.50 a.m. on 26 September the five layers of barrage fired by the British artillery and machine-guns began. Dust and smoke added to the morning mist so the infantry advanced using compass bearings. Each of the three German ground-holding divisions attacked on 26 September had an Eingreif division in support, twice the ratio of 20 September. No ground captured by the British was lost and German counter-attacks managed only to reach ground to which survivors of the front-line divisions had retired.

Battle of Broodseinde: 4 October
The Battle of Broodseinde was the last assault launched by Plumer in good weather. The operation aimed to complete the capture of the Gheluvelt Plateau and occupy Broodseinde Ridge. The Germans sought to recapture their defences around Zonnebeke with a methodical counter-attack also on 4 October. On 4 October the British attacked along a 14000 yd front. By coincidence, Australian troops from I Anzac Corps met attacking troops from the German 45th Reserve Division in no man's land when Operation Hohensturm commenced simultaneously. The Germans had reinforced their front line to delay the British capture of their forward positions until the Eingreif divisions could intervene, which brought more German troops into the area most vulnerable to the British artillery. The success of the British advance varied but the losses inflicted on the Germans were devastating.

German defensive changes
On 7 October the German Fourth Army again dispersed its troops in the front defence zone. Reserve battalions moved back behind the artillery protective line and the Eingreif divisions were organised to intervene as swiftly as possible once an attack commenced, despite the risk of being devastated by the British artillery. Counter-battery fire to reduce British artillery fire were to be increased to protect the Eingreif divisions as they advanced. All of the German divisions holding front zones were relieved and an extra division brought forward as the British advances had lengthened the front line. Without the forces necessary for a counter-offensive south of the Gheluvelt plateau towards Kemmel Hill, Rupprecht began to plan for a slow withdrawal from the Ypres salient, even at the risk of uncovering German positions further north and the Belgian coast.

Battle of Poelcappelle: 9 October
The French First Army and British 2nd and 5th armies attacked on 9 October on a 13500 yd front, from south of Broodseinde to St Jansbeek, to advance half of the distance from Broodseinde ridge to Passchendaele on the main front, which led to many casualties on both sides, with advances in the north of the attack being retained by British and French troops and most of the ground taken in front of Passchendaele and on the Becelaere and Gheluvelt spurs being lost to German counter-attacks. Birdwood later wrote that the return of heavy rain and mud sloughs, was the main cause of the failure to hold captured ground. General von Kuhl concluded that the fighting strained German fighting power to the limit but that the German forces managed to prevent a breakthrough although it was becoming much harder to replace losses.

First Battle of Passchendaele: 12 October
The First Battle of Passchendaele, on 12 October was another Allied attempt to gain ground around Passchendaele. The heavy rain and mud again made movement difficult and little artillery could be brought closer to the front. Allied troops were exhausted and morale had fallen. After a modest British advance, German counter-attacks recovered most of the ground lost opposite Passchendaele. There were 13,000 Allied casualties, including 2,735 New Zealanders, 845 of whom were either dead or wounded and stranded in the mud of no-man's-land. In lives lost in a day, this is the blackest day in New Zealand history. At a conference on 13 October, Haig and the army commanders agreed that attacks would stop until the weather improved and roads would be extended, to carry more artillery and ammunition forward for better fire support.

Battle of Malmaison: 23 October – 2 November
After numerous requests from Haig, Petain began the Battle of La Malmaison, a long-delayed French attack on the Chemin des Dames, by Maistre's Sixth Army. The artillery preparation started on 17 October, four months late. The Germans were swiftly defeated, losing 11,157 prisoners and 180 guns, as the French advanced up to 3.7 mi, capturing the village and fort of La Malmaison, gaining control of the Chemin des Dames ridge. The Germans had to withdraw to the north of the Ailette Valley. Haig was pleased with the French success but regretted the delays which had lessened its effect on the Flanders operations.

Second Battle of Passchendaele: 26 October – 10 November
The British Fifth Army undertook minor operations 20–22 October to maintain pressure on the Germans while the Canadian Corps prepared for their assault, as well as supporting the French attack at Malmaison. The four divisions of the Canadian Corps had been transferred to the Ypres Salient to capture Passchendaele and the ridge. The Canadian Corps relieved II Anzac Corps on 18 October from their positions along the valley between Gravenstafel Ridge and the heights at Passchendaele. The front line was mostly the same as the one occupied by the 1st Canadian Division in April 1915. The Canadian Corps operation was to be executed in a series of three attacks each with limited objectives, delivered at intervals of three or more days. The dates of the phases were tentatively given as 26 October, 30 October and 6 November. The first stage began on the morning of 26 October. The 3rd Canadian Division captured Wolf Copse and secured its objective line and then swung back its northern flank to link up with the adjacent division of the British Fifth Army. The 4th Canadian Division captured its objectives but gradually retreated from Decline Copse due to German counter-attacks and communication failures between the Canadian and Australian units to the south.

The second stage began on 30 October and was intended to complete the previous stage and gain a base for the final assault on Passchendaele. The southern flank quickly captured Crest Farm and sent patrols beyond its objective line and into Passchendaele. The northern flank again met with exceptional German resistance. The 3rd Canadian Division captured Vapour Farm on the Corps boundary, Furst Farm to the west of Meetcheele and the crossroads at Meetcheele but remained short of its objective. During a seven-day pause, the British Second Army took over a section of the British Fifth Army front adjoining the Canadian Corps. Three rainless days from 3–5 November eased preparation for the next stage, which began on the morning of 6 November with the 1st and 2nd Canadian Divisions. In fewer than three hours, many units had reached their final objectives and the village of Passchendaele had been captured. The Canadian Corps launched a final action on 10 November to gain control of the remaining high ground north of the village, in the vicinity of Hill 52. The attack on 10 November brought an end to the campaign.

Analysis
In a German General Staff publication it was written that "Germany had been brought near to certain destruction (sicheren Untergang) by the Flanders battle of 1917". In his memoirs (1938) Lloyd George wrote, "Passchendaele was indeed one of the greatest disasters of the war ... No soldier of any intelligence now defends this senseless campaign ...". G. C. Wynne wrote that the British had eventually reached Passchendaele Ridge and captured Flandern I; beyond them was Flandern II and also Flandern III, which was nearly complete. The German submarine bases on the coast remained but the objective of diverting the Germans from the French further south, while they recovered from the failure of the Nivelle Offensive in April had succeeded. Paddy Griffith wrote that the bite and hold system kept moving until November because the BEF had developed a workable system of offensive tactics against which the Germans ultimately had no answer.

In 2007 Jack Sheldon wrote that relative casualty figures were irrelevant, because the German army could not afford heavy losses or lose the initiative, by being compelled to fight another defensive battle on ground of the Allies' choosing. The Third Battle of Ypres pinned the German army to Flanders and cost unsustainable casualties. At an army commanders' conference on 13 October a scheme of Byng's British Third Army for mid-November was discussed. Byng wanted the operations at Ypres to continue so as to hold German troops in Flanders. The Battle of Cambrai began on 20 November when the British breached the first two parts of the Hindenburg Line in the first successful mass use of tanks in a combined arms operation.

The experience of the failure to contain the British attacks at Ypres and the drastic reduction in areas of the western front which could be considered "quiet", after the tank and artillery surprise at Cambrai, left the German Oberste Heeresleitung with little choice but to return to a strategy of decisive victory in 1918. On 24 October, the Austro-German 14th Army, under General der Infanterie Otto von Below, attacked the Italian Second Army on the Isonzo at the Battle of Caporetto and in 18 days, Italy lost 650,000 men and 3,000 guns. In fear that Italy might be put out of the war, the French and British Governments offered reinforcements. British and French troops were swiftly moved from 10 November – 12 December. The diversion of resources from the BEF, forced Haig to conclude the 3rd Battle of Ypres short of Westrozebeke, the last substantial attack being made on 10 November.

Casualties
Various casualty figures have been published, sometimes with acrimony, although the highest estimates for British and German casualties appear to be discredited. In the Official History, Brigadier-General J. E. Edmonds put British casualties at 244,897 and claimed that equivalent German figures were not available, estimating German losses at 400,000. Edmonds considered that 30% needed to be added to German statistics to make them comparable with British casualty criteria. In 2007, Sheldon wrote that although German casualties from 1 June – 10 November were 217,194, a figure available in Volume III of the Sanitätsbericht (1934, Medical Report Concerning the German Army 1914–1918), Edmonds may not have included them as they did not fit his case. Sheldon recorded 182,396 slightly wounded and sick soldiers not struck off unit strength, which if included would make 399,590 German losses. The British claim to have taken 24,065 prisoners has not been disputed.

Commemoration
The Menin Gate Memorial to the Missing. commemorates those of all Commonwealth nations, except New Zealand, who died in the Ypres Salient and have no known grave. In the case of the United Kingdom only casualties before 16 August 1917 are commemorated on the memorial. United Kingdom and New Zealand servicemen who died after that date are named on the memorial at Tyne Cot Cemetery. There are numerous tributes and memorials all over Australia and New Zealand to ANZAC soldiers who died in the battle, including plaques at the Christchurch and Dunedin railway stations. The Canadian Corps participation in the Second Battle of Passchendaele is commemorated with the Passchendaele Memorial located at the former site of the Crest Farm on the south-west fringe of Passchendaele village. One of the newest monuments to be dedicated to the fighting contribution of a group is the Celtic Cross memorial commemorating the Scottish contributions and efforts in the fighting in Flanders during the Great War. This memorial is located on the Frezenberg Ridge where the Scottish 9th and 15th Divisions, as part of the British Army, fought during the Battle of Passchendaele. The monument was dedicated by the Scottish Parliament's Minister for Europe Linda Fabiani during the late summer of 2007, the 90th anniversary of the battle.