1917: July 31
On July 31, the offensive known as the Battle of Passchendaele, or the Third Battle of Ypres, was launched by the Allies. The battle lasted three months and became notorious as one of the most costly and controversial Allied offensives of the Western Front due to the relatively small territorial gain for the number of soldiers lost; accurate casualty figures remain elusive but it’s generally accepted that at least 300,000 Allied and at least 260,000 German soldiers were either killed, wounded or lost beneath the Flanders mud.
British Field Marshal Douglas Haig, who was in charge of the offensive, has been criticised by some historians for having unrealistically ambitious aims, a misguided persistence that capturing Ypres would break a supposedly weak German line and a supposed over-readiness to throw masses of troops to their death.
Haig had been informed that the immediate objective was to destroy German submarine bases in Flanders to ensure the continued naval success of the British into at least 1918. Although Haig understood the immediacy of the command, he optimistically believed that the Germans were weaker than they actually were, a view he had previously held at the also loss-heavy Somme offensive a year earlier. Haig believed that capturing the Passchendaele ridge would break German morale once and for all, and sent wave after wave of soldiers into the field.
To oversee the battle Haig chose General Hubert Gough, who agreed with Haig’s tactic of large-scale sweeping offensives; Gough was, like Haig, prepared to relentlessly ‘keep sending men’ all at once into no-man’s land. The Allies were also hampered by the heaviest rain seen in the region for thirty years which, along with the Allied tactic of shelling the German lines in a ten-day bombardment before the offensive, created a zone made for killing; the heavy shelling took away any element of surprise and the German defenders were ready for the Allies who had to attack through a cratered swamp. This resulted in heavy losses of men not just to the guns but also the mud, which sucked in the fatigued and sleep deprived soldiers. The Allies, who were also unable to deploy their tanks due to the ground conditions, failed in their initial objectives, prompting Haig to replace Gough with General Herbert Plumer, the creative tactician who had won the capture of the Messines-Wytschaete ridge on June 7, who favoured a strategy of seeking regular but smaller territorial gains rather than sweeping offensives to achieve a major breakthrough.
By the end of September, the British were able to establish control over a ridge of land east of the town of Ypres. Meanwhile the Germans were able to reinforce their troops at Passchendaele Ridge thanks to men arriving from the now-quiet Eastern Front and the widespread use of mustard gas. Despite the exhaustion of the British troops, Haig ordered a final three attacks on Passchendaele in late October. Allied losses mounted but on November 6, British and Canadian troops managed to take control of Passchendaele Ridge. They had advanced five miles since the beginning of the battle and Haig was finally able to call off the offensive while claiming a victory, albeit at a great human cost.