At 3:50 in the morning of 31 July 1917, after a huge artillery bombardment, British and French infantry attacked the German lines around Ypres in Belgian Flanders. It was the first day of the Third Battle of Ypres, better known as Passchendaele. The attackers gained ground at Pilckem Ridge, but that afternoon heavy rain began, and the shattered ground turned to swamp. The offensive went on until November, when Canadian troops finally took the village and ridge of Passchendaele, at a cost of hundreds of thousands of casualties on both sides.
Haig's plan
After the Arras offensive earlier in 1917, the British commander, Sir Douglas Haig, planned a major attack out of the Ypres salient to force the breakthrough he believed would win the war. The aim was to take the high ground around Ypres, including the Passchendaele ridge, and then push on to the Belgian coast, removing a threat from German submarines operating out of Belgian ports.1
The infantry attack was prepared by a vast bombardment. The National Army Museum describes two weeks of shelling in which 3,000 guns fired millions of shells at the German positions; Mark Cartwright, in the World History Encyclopedia, calls it the heaviest barrage yet seen in the war, with at least three times the shells fired in the Battle of the Somme in 1916. Both note that the shelling also wrecked the delicate drainage of the low Flanders plain.2
Pilckem Ridge and the rain
The British Fifth and Second Armies and the French First Army went over the top on 31 July. On that first day, at Pilckem Ridge, the British and particularly the French made some gains, though not without cost, and Cartwright puts the advance at about two miles before the attack was stopped. The Germans used their reserves, held back in depth, to counterattack.3
Then the weather turned. The National Army Museum says it began to rain heavily in the afternoon of 31 July; British artillery observers lost sight of the advancing troops and could not support them against German counterattacks, so captured ground was lost. Veterans Affairs Canada notes that heavy rain fell the very night the ground assault began and that shell holes quickly filled with water. With the drainage destroyed, the battlefield became a swamp in which men and guns could barely move, and by 2 August the offensive had to be postponed.4
Three months to the ridge
The battle dragged on through August. In September General Herbert Plumer's bite and hold attacks, on narrow fronts with heavy artillery support, made better progress at the Menin Road, Polygon Wood and Broodseinde. But the rain returned, and in October Haig called in the Canadian Corps. Its commander, Lieutenant-General Arthur Currie, objected but was overruled; the Canadians attacked on 26 October, captured the ruined village of Passchendaele on 6 November and cleared the ridge on 10 November.5
The cost is still argued over. The National Army Museum gives 300,000 British casualties and around 260,000 German; Cartwright gives 250,000 to 275,000 British and Empire casualties, including 70,000 killed, against around 220,000 German. Veterans Affairs Canada counts more than 4,000 Canadian dead and almost 12,000 wounded. Haig considered the battle a success, but the National Army Museum notes that the British gave up the Passchendaele ridge without a fight in 1918 to shorten their line against the German spring offensive. The full story is in our article on the Battle of Passchendaele.6
Also on this day
- 1760: Battle of Warburg. Near Warburg on the Diemel river, the British and Hanoverian army of Ferdinand of Brunswick attacked a French corps during the Seven Years' War.
