On August 16, 1917, in a renewed thrust of the Allied offensive launched at the end of July in the Flanders region of Belgium—known as the Third Battle of Ypres, or simply as Passchendaele, for the village that saw the heaviest fighting—British troops capture the village of Langemarck from the Germans.
The ambitious, meticulously planned offensive, masterminded by the British commander in chief Sir Douglas Haig, began on July 31 with a British and French attack on German positions near the village of Passchendaele, located in Flanders in the much-contested Ypres Salient. After the initial assault met with less success than had been anticipated, heavy rains and thickening mud bogged down the Allied infantry and artillery and prevented them from renewing the offensive until the second week of August. On August 16, at Langemarck, to the west of Passchendaele, four days of fierce fighting resulted in a British victory; the gains were small, however, for the high number of casualties incurred.
Though a German counterattack recovered much of the ground gained at Langemarck, British forces retained the initiative in the region, aided by the use of tanks and by a diversionary attack by the French at Verdun, where more than 5,000 German soldiers were taken prisoner. By the end of September, the British were able to establish control over the ridge of land to the east of Ypres, and Haig pushed his commanders in the region to continue the attacks towards the Passchendaele ridge. As the offensive stretched into October, Allied troops reached near-exhaustion as the Germans reinforced their positions in the region with reserve troops released from the Eastern Front.
After Canadian and British troops finally captured Passchendaele on November 6, 1917, Haig called off the offensive, claiming victory for his men. In sum, a total of some 310,000 British casualties, as opposed to 260,000 on the German side, and a failure to create any substantial breakthrough on the Western Front, made the Third Battle of Ypres one of the most costly and controversial offensives of World War I.