World War I: Second Battle of Ypres

Horace Smith-Dorrien
Photograph Source: Public Domain

The Second Battle Ypres was fought April 22 to May 25, 1915, during World War I (1914-1918) and saw the Germans conduct a limited offensive around the strategic town of Ypres in Flanders. During the course of the battle, the Germans debuted the use of poison gas on the Western Front. This new technology provided an initial advantage, but the Germans were ultimately stopped after heavy fighting. Though the Germans had not achieved a breakthrough, they succeeded in bringing Ypres within range of their artillery.


With the German defeat at the First Battle of the Marne in September 1914 and the unraveling of the Schlieffen Plan, both sides commenced a series of flanking maneuvers in northern France and Flanders. As the two sides sought an advantage, they clashed in Picardy, Albert, and Artois. Finally reaching the coast, the Western Front became a continuous line stretching to the Swiss frontier. In October, the Germans attempted to breakthrough at the town of Ypres in Flanders. This resulted in the First Battle of Ypres which saw the Allies hold a salient around Ypres after brutal fighting.

Conflicting Strategies

As trench warfare continued, both sides began assessing their options for bringing the war to a successful conclusion. Overseeing German operations, Chief of the General Staff Erich von Falkenhayn preferred to focus on winning the war on the Western Front as he believed that a separate peace could be obtained with Russia. This approach clashed with General Paul von Hindenburg who wished to deliver a decisive blow in the East.

Erich von Falkenhayn
Chief of the General Staff Erich von Falkenhayn. Public Domain

The hero of Tannenberg, he was able to use his fame and political intrigue to influence the German leadership. As a result, the decision was made to focus on the Eastern Front in 1915. This focus ultimately resulted in the stunningly successful Gorlice-Tarnów Offensive in May.

An Offensive in the West

Though Germany had elected to follow an "east-first" approach, Falkenhayn started planning for an operation against Ypres to begin in April. Intended as a limited offensive, he sought to divert Allied attention from troop movements east, secure a more commanding position in Flanders, as well as to test a new weapon, poison gas. Though tear gas had been used against the Russians in January at Bolimov, the Second Battle of Ypres would mark the debut of lethal chlorine gas.

In preparation for the assault, German troops moved 5,730 90 lb. canisters of chlorine gas to the front opposite Gravenstafel Ridge which was occupied by French 45th and 87th Divisions. These units were comprised of territorial and colonial troops from Algeria and Morocco.

Armies & Commanders



  • Albrecht, Duke of Württemberg
  • 7 divisions

The Germans Strike

Around 5:00 PM on April 22, 1915, troops from Albrecht, Duke of Württemberg's German 4th Army began releasing the gas towards the French troops at Gravenstafel. This was done by opening the gas cylinders by hand and relying on the prevailing winds to carry the gas towards the enemy. A dangerous method of dispersal, it resulted in numerous casualties among the German forces. Drifting across the lines, the grey-green cloud struck the French 45th and 87th Divisions.

Duke Albrecht of Württemberg
Albrecht, Duke of Württemberg. Public Domain

Unprepared for such an attack, the French troops began retreating as their comrades were blinded or collapsed from asphyxiation and damage to lung tissue. As the gas was denser than air it quickly filled low-lying areas, such as trenches, forcing the surviving French defenders into the open where they were susceptible to German fire. In short order, a gap of around 8,000 yards opened in the Allied lines as around 6,000 French soldiers died from gas-related causes. Moving forward, the Germans entered the Allied lines but their exploitation of the gap was slowed by darkness and a lack of reserves.

Closing the Breach

To seal the breach, the 1st Canadian Division of General Sir Horace Smith-Dorrien's Second British Army was shifted to the area after dark. Forming up, elements of the division, led by the 10th Battalion, 2nd Canadian Brigade, counterattacked at Kitcheners' Wood around 11:00 PM. In a brutal battle, they succeeded in reclaiming the area from the Germans but sustained high casualties in the process. Continuing pressure on the northern part of the Ypres Salient, the Germans released a second gas attack on the morning of the 24th as part of an effort to take St. Julien.

The Allies Fight to Hold On

Though the Canadian troops attempted to improvise protective measures such as covering their mouths and noses with water or urine-soaked handkerchiefs, they were ultimately forced to fall back though they exacted a high price from the Germans. Subsequent British counterattacks over the next two days failed to retake St. Julien and the units engaged sustained heavy losses. As fighting spread down the salient as far as Hill 60, Smith-Dorrien came to believe that only a major counter-offensive would be able to push the Germans back to their original positions. 

Herbert Plumer
Field Marshal Herbert Plumer. Library of Congress

As such, he recommended withdrawing two miles to a new line in front of Ypres where his men could consolidate and re-form. This plan was rejected by the Commander-in-Chief of the British Expeditionary Force, Field Marshal Sir John French, who elected to sack Smith-Dorrien and replace him with the commander of V Corps, General Herbert Plumer. Assessing the situation, Plumer also recommended falling back. Following the defeat of a small counter-offensive led by General Ferdinand Foch, French directed Plumer to begin the planned retreat.

New German Attacks

As the withdrawal began on May 1, the Germans again attacked with gas near Hill 60. Assaulting the Allied lines, they were met by fierce resistance from the British survivors, including many from the 1st Battalion of the Dorset Regiment, and were turned back. Having consolidated their position, the Allies were again attacked by the Germans on May 8. Opening with a heavy artillery bombardment, the Germans moved against the British 27th and 28th Divisions southeast of Ypres on Frezenberg Ridge. Meeting heavy resistance, they released a gas cloud on May 10.

Having endured earlier gas attacks, the British had developed new tactics such as shelling behind the cloud to strike at the advancing German infantry. In six days of bloody fighting, the Germans were only able to advance around 2,000 yards. After a pause of eleven days, the Germans resumed the battle by releasing their largest gas attack to date across a 4.5-mile section of the front. Beginning before dawn on May 24, the German assault sought to capture Bellewaarde Ridge. In two days of fighting, the British bloodied the Germans but were still forced to concede another 1,000 yards of territory.


After the effort against Bellewaarde Ridge, the Germans brought the battle to a close due to a lack of supplies and manpower. In the fighting at Second Ypres, the British suffered around 59,275 casualties, while the Germans endured 34,933. In addition, the French incurred around 10,000. Though the Germans had failed to break through the Allied lines, they reduced the Ypres Salient to around three miles which allowed for the shelling of the city. In addition, they had secured much of the high ground in the area.

The gas attack on the first day of the battle became one of the conflict's great missed opportunities. Had the assault been backed with sufficient reserves, it may have broken through the Allied lines. The use of poison gas had come as a tactical surprise to the Allies who roundly condemned its use as barbaric and reprehensible. Though many neutral nations agreed with this assessment, it did not stop the Allies from developing their own gas weapons which debuted at Loos that September. The Second Battle of Ypres is also notable for being the engagement during which Lieutenant Colonel John McCrae, MD composed the famed poem In Flanders Fields.

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Hickman, Kennedy. "World War I: Second Battle of Ypres." ThoughtCo, Jul. 31, 2021, Hickman, Kennedy. (2021, July 31). World War I: Second Battle of Ypres. Retrieved from Hickman, Kennedy. "World War I: Second Battle of Ypres." ThoughtCo. (accessed June 6, 2023).