31 July - 10 November 1917

First World War 

The Third Battle of Ypres - also known as Passchendaele - has shaped perceptions of the First World War on the Western Front. Fought between July and November 1917, both sides suffered heavy casualties and endured appalling conditions. The name Passchendaele has become synonymous with mud, blood and futility.

In 1917, General Sir Douglas Haig planned a major offensive to break out of the Ypres salient, which the Allies had occupied since 1914. 

Haig's vision was for a war-winning breakthrough. He planned to capture the high ground around Ypres, as well as a key rail junction to the east, and then advance on the German-occupied ports of the Belgian coast - critical to the U-Boat campaign.

The battle failed to achieve Haig's objectives. It lasted over 100 days. In that time, the Allies advanced about 5 miles for the loss of over 250,000 soldiers killed, wounded or missing.


5 Facts About the Third Battle of Ypres

Discover more about the Third Battle of Ypres and a few highlights from our collection.


1. The Battle began on 31 July 1917

Battle of Pilckem Ridge. British troops loading a pack horse with wiring staples. Note the horse's gas-mask. Near Pilckem, 31 July 1917.
© IWM Q 5717

After a two-week artillery bombardment, the Third Battle of Ypres began on 31 July. 

On the first day, British and French forces made significant gains in some sectors. As the day wore on, it began to rain heavily. The rain made it difficult for the artillery to support the advance. The German defensive system was designed to wear attacking forces down before pushing them back with powerful counterattacks. Having advanced deep into this system, and lacking effective artillery support, the Allies were vulnerable to these counterattacks and lost much of the territory they had gained.


2.Rain and mud defined the battle

The rain began on 31 July - the first day of the battle. The battlefield had been churned up by the Allied artillery bombardment, destroying the ditches that acted as a drainage system.

The rain continued for three weeks. Soldiers struggled through heavy, sticky mud that reached up to their waists. Men, horses, tanks and other vehicles literally drowned in the mud. It was almost impossible to manoeuvre artillery into new positions, and aerial reconnaissance was grounded by the poor visibility.


3. Stages of the battle were successful

The Third Battle of Ypres is perceived as muddy, bloody and futile. The early and latter stages of the battle largely conform to this image but the middle stages were very successful.

In September, General Herbert Plumer replaced General Hubert Gough as commander. He introduced a new approach. Instead of attacking along a wide front and setting ambitious objectives deep inside the German defensive system, Plumer favoured a 'bite and hold' strategy.


Better weather and better tactics

He set limited objectives, making sure the attack was always within range of artillery support. Once they reached their objective, troops dug in to prepare for counterattacks.

Plumer's new approach was also helped by improved weather conditions in September. Better weather meant more artillery and aerial reconnaissance to support the attack. Although they continued to suffer heavy casualties, the Allies made significant progress at the Menin Road, Polygon Wood and Broodseinde.


4. Passchendaele was the final objective

The Third Battle of Ypres is often called Passchendaele. It's been referred to by this name since the 1920s. The village of Passchendaele - and Passchendaele Ridge - were objectives in the final stages of the offensive.

The rain returned in October. Despite worsening conditions and exhausted troops, Haig decided to continue the offensive in order to capture Passchendaele Ridge. The heavy casualties and appalling conditions suffered during the advance on Passchendaele perhaps contributed to the use of the name to refer to the battle as a whole.


5.Casualties were heavy

The Allies suffered over 250,000 casualties - soldiers killed wounded or missing - during the Third Battle of Ypres. Casualties among German forces were also in the region of 200,000. The Commonwealth War Graves Commission commemorates over 76,000 soldiers who died during the Third Battle of Ypres. More than half have no known grave.

The German Army could not afford the losses it incurred at Ypres. While the Allies would soon be reinforced by the Americans, Germany could not replace that manpower.

Personal Stories of the Battle

Photo of Harry Patch taken by Don McCullin © Crown copyright.
© Crown copyright. IWM (2009-09-24)
First World War

Lance Corporal Henry John - Harry Patch

Harry Patch took part in the Third Battle of Ypres, or Passchendaele, but for decades, he did not speak of his service and what he had seen. However at the age of 100, he began sharing his story of the war and would come to be known as 'The Last Fighting Tommy'. 

Individual head and shoulder portraits of Private John William Mudd and his wife Elizabeth
@IWM HU 57199 / @IWM HU 57198
First World War

'I love you more than ever…'

The story of a poignant letter home sent by a soldier who fought at the Battle of Passchendaele.

Men of the West Yorkshire Regiment sitting in a captured German pill box waiting to go into action, near the St Julien - Grafenstafel road during the Battle of Polygon Wood, 26 September - 3 October, part of the Battle of Passchendaele.
First World War

Voices of the First World War: Passchendaele

Episode 31: The Ypres Salient was one of the most intensely fought over sections of the Western Front. Hear about the British high command's plans in early 1917 to seize control of the area once and for all.

Welsh Poet, Hedd Wyn
First World War

Hedd Wyn - Private Ellis Humphrey Evans

In July 1917, Welsh poet Hedd Wyn posted a poem titled Yr Arwr (The Hero) back to Wales from a village in France.

Photograph of Douglas Clark, a rugby player who fought at the Third Battle of Ypres
First World War

Acting Sergeant Douglas Clark

Douglas Clark is regarded as one of the greatest ever Rugby League forwards and was enjoying a successful sporting career before the outbreak of the First World War. But by 1917, he was among the British soldiers fighting in the Battle of Passchendaele.