III.

Second Battle of Ypres

On April 22, 1915, the German Fourth Army launched a new attack at Ypres. This was a limited offensive and, to a large extent, was an experiment in the use of a new weapon: poisonous chlorine gas. The gas was released against French units on the northern face of the salient. Taken completely by surprise they fled, leaving an 8 km (5 mi) gap in the Allied line. The Germans failed to recognize the extent of their success, and moved slowly to exploit it, allowing troops from the British Second Army, including the First Canadian Division, to form a new line. The German attacks continued until May 25, with the further use of gas. The commander of the Second Army, General Sir Horace Smith-Dorrien, asked Sir John French for permission to withdraw nearer the town. French replaced him with General Sir Herbert Plumer, but then relented and permitted Plumer to shorten the British line, leaving a shallow salient before Ypres. Allied casualties amounted to 70,000 men, while the Germans suffered 35,000 losses.