Second Battle of Ypres

Background

By the spring of 1915 the Western Front had settled into trench warfare. The First Battle of Ypres the previous autumn had left the Allies holding Ypres, the last sizeable Belgian town in their hands, at the centre of a salient that bulged east of the town, with valuable higher ground to its east and south. The Belgians held the Yser to the north, two French divisions the northern face of the salient, and the 1st Canadian Division and two British divisions its eastern bulge.

The German Chief of the General Staff, Erich von Falkenhayn, was not seeking a decision in the west. His main effort was moving east, where the Gorlice–Tarnów offensive against the Russians opened in May, and the Ypres attack was the only German offensive on the Western Front that year. It was meant to cover those transfers, to pinch out or shrink the salient, and to try a new weapon. The chemist Walther Nernst had suggested emptying enemy trenches with gas; Fritz Haber proposed chlorine instead, which is heavier than air and would sink into trenches. A tear-gas trial at Bolimov on the Eastern Front earlier in the year had failed when the gas froze.

German troops carried some 5,730–6,000 cylinders into the front line north of the salient, the largest weighing 40 kg, and installed them under the supervision of Haber, Otto Hahn, James Franck and Gustav Hertz; then they had to wait for a wind blowing towards the Allied lines. Few reserves were set aside to exploit success, and whether Falkenhayn ever meant to reach the Channel ports is doubted.

The armies

Duke Albrecht of Württemberg's 4th Army made the attack. The gas assault of 22 April fell to General von Kathen's XXIII Reserve Corps and General von Hügel's XXVI Reserve Corps, with five reserve divisions; XXVII Reserve Corps near Gheluvelt and XV Corps near Hollebeke joined the later attacks. The pioneers of Pionier-Regiment 35 released the gas. The German infantry following it had only cotton pads soaked in sodium thiosulphate for protection.

The salient belonged to General Sir Horace Smith-Dorrien's British Second Army. Its V Corps, under General Sir Herbert Plumer, held the eastern face with the regular 27th and 28th Divisions and the 1st Canadian Division under Edwin Alderson; the 4th, the Territorial 50th (Northumbrian) and the Indian Lahore Divisions came in as the battle went on. The Canadians had been civilians only months before. They had capable artillery but used linear tactics against magazine rifles and machine guns, and their Ross rifles jammed in the fighting.

The northern face was French: General Putz's Détachement d'armée de Belgique with the 87th Territorial Division, older reservists from the Rennes military district, and the 45th Division of the Army of Africa, with Zouaves, Algerian tirailleurs and African light infantry. No Allied soldier had any protection against gas.

The battle

CDB90 treats the five weeks as one engagement, Ypres II (291). The British count four battles within it.

Gravenstafel, 22–23 April. At about 17:00 on 22 April, with a light north-easterly breeze, the Germans opened the cylinders on a front of about 6.5 km between Langemark and Gravenstafel and released around 150–170 tonnes of chlorine in a few minutes. The cloud drifted onto the 87th Territorial and 45th Divisions. Men ran from it, in the words of Colonel Henri Mordacq of the 45th Division's 90th Brigade, 'running like madmen, directionless, shouting for water, spitting blood'. A gap of about 6 km opened between the canal and the Canadian left. The German infantry, following well behind the cloud, took Langemark and Pilckem, about 2,000 prisoners and 51 guns, then stopped and dug in some 3 km forward rather than push on towards Ypres.

For some hours the gap was held only in patches: by French Zouaves and tirailleurs, by the left of the 3rd Canadian Brigade bent back towards St Julien, and by scratch British battalions gathered at St Jean as 'Geddes's Detachment'. Smith-Dorrien released the 1st Canadian Brigade at 20:00. At 23:46 the 10th and 16th Canadian Battalions, more than 800 men, attacked Kitcheners' Wood, an oak plantation near St Julien, without reconnaissance; they cleared it at the cost of about three-quarters of their number. On 23 April the Germans took Steenstrate and Lizerne on the canal.

St Julien, 24 April–4 May. Early on 24 April a second cloud was released against the Canadian 8th and 15th Battalions in the re-formed line near St Julien. Men breathed through handkerchiefs soaked in water or urine. The 15th Battalion lost all eleven of its front-line officers and fell back; the 13th Battalion's machine-gunners, among them Lance-Corporal Frederick Fisher, had already held the village's approaches, and by the end of the day St Julien had fallen. It was the Canadians' worst day: 3,058 casualties. British reinforcements counter-attacked: the York and Durham brigades of the Northumbrian Division on 25 April, the Northumberland Brigade on 26 April, losing 1,954 men; the Lahore Division also came into the fight. French counter-attacks under Foch retook Lizerne on 27 April.

That day Smith-Dorrien proposed falling back to the shorter GHQ Line. Sir John French gave the salient to Plumer instead, who then asked for almost the same withdrawal. Between 1 and 4 May the 1st Canadian, 27th and 28th Divisions pulled back to a line closer to Ypres. On 6 May Smith-Dorrien was removed and Plumer took over Second Army.

Frezenberg, 8–13 May. The Germans brought their field guns forward and massed three corps against the 27th and 28th Divisions on Frezenberg ridge. On 8 May the 83rd Brigade, on the forward slope, beat off two assaults but was driven back by the third; the 84th Brigade was pushed back too, leaving a gap of about two miles. Princess Patricia's Canadian Light Infantry, about 700 strong, held on at the cost of all but about 150 men, and the 10th Brigade moved up overnight to close the line.

Bellewaarde, 24–25 May. On 24 May a last gas attack struck around Shell Trap Farm. The Germans took the trenches to the north, but the 2nd Royal Dublin Fusiliers, who had been warned, held theirs with the 9th Argyll and Sutherland Highlanders. On 25 May the German high command called the offensive off.

Aftermath

The Allies kept Ypres, but they now held a smaller salient whose line ran about three miles closer to the town, with the Germans on the higher ground. Shelling had largely destroyed Ypres and its last civilians left in May. British Empire losses were about 55,000–59,000, among them nearly 6,000 Canadians; German losses were about 35,000. French losses remain uncertain, from 2,000–3,000 gas casualties to more than 20,000 on the British official history's counting.

The gas surprised the Allies but did not win the battle. Some 7,000 gas casualties passed through British medical units, and 350 British gas deaths were recorded in May and June. Improvised respirators followed within weeks, gas helmets later in the year, and the British used gas themselves at Loos in September. It has been called one of the war's great missed chances: the Germans had no reserves to exploit their breach.

For Canada the battle was the first great test, which gave its troops a reputation as tough and dependable. On 3 May John McCrae, medical officer of the 1st Canadian Field Artillery Brigade, after burying his friend Alexis Helmer, wrote 'In Flanders Fields', published in Punch on 8 December 1915; its poppies became the emblem of remembrance. Smith-Dorrien's removal is still argued over: Edmonds, the official historian, alleged he was cleared out of Haig's way, but his long antipathy with French is the likelier cause.

Wargaming it

Second Ypres gives two very different games. The first is the night of 22–23 April at battalion or company scale (a stand as a company), on about 8 km of front from the canal to Gravenstafel. The German player has a devastating opening, no gas masks and too few reserves; the Allied player has a gap held by Zouaves, Canadians and scratch British battalions, and must decide whether to counter-attack in the dark, as at Kitcheners' Wood, or simply hold St Julien and St Jean until help arrives.

The second is a set-piece defence: 24 April at St Julien or 8 May at Frezenberg, at company or platoon scale, with gas, heavy artillery from three sides and counter-attacks by fresh British brigades. Forward-slope trenches, farms and the woods are the key terrain, and observation from the low ridges matters more than their height suggests.

Rules should make the gas uncertain: it depends on the wind, drifts and lingers, and the attacker hesitates to follow it. Jamming Ross rifles and green Canadian and Territorial units add friction. The 'what ifs' are tempting: German reserves on the evening of 22 April, a different wind, or Smith-Dorrien's withdrawal accepted on 27 April. A brigade-scale campaign of the whole five weeks lets players argue whether the salient was worth holding at all.

Maps and pictures

Pictures from the time

Photographs by the armies' photographers and the press, and drawings made at the time: free-to-use pictures from the battle's category on Wikimedia Commons. Each opens its file page there, with the full caption and source.