The second Battle of Ypres was in fact a series of four engagements. Initially planned by the Germans as a local tactical battle to straighten their lines near Ypres, their use of gas on the battlefield in the west for the first time impacted the battles for the rest of the war.

The battle began late in the afternoon of April 22nd. German troops released chlorine gas over a front being held by French colonial troops. The French were not prepared for the attack and 6,000 troops in the path of the gas quickly became casualties. This created a large gap in the allied lines. However the German were unable to fully exploit that gap due to shortage of troops and the effective defense of the Canadian troops who were located on the flanks.

The attacks had caused the line to move behind the village of St Julien which now became the focus of the battle . The German once again attacked with gas this time against the Canadian troops on April 24th. The troops had learned that if you covered your face in something soaked in urine you could partially counter the effects of the gas. Despite this the gas opened up a large gap in the Allied lines. However, the Germans were not able to attack through the gas, and by the time the gas had disbursed Canadian and British troops were able to reoccupy the positions that they held previously.

The third attack occurred on May 8th on a strategic ridge called the Frezenberg ridge. The German had moved field artillery forward to use in the attack and began it with large bombardment of the Canadian and British lines. After their artillery bombardment the Germans began their assault. The first two waves were turned back by the remaining Allied troops, but their third assault succeeded in breaking through, creating a 2 mile gap in the lines. However heroic counterattack by the Princess Patricia’sCanadian Light Infantry stopped the German assault and stabilized the line.

The fourth attack occurred on May 24th when the Germans once again attacked with poison gas. Once again the defenders tried to hold back the Germans but they were once again overwhelmed. By the end of the day the lines were pushed back over a mile.

Once again like all the battle on the Western Front not much changed. The Germans managed to advance a few mile and compress what was called the Ypres Salient so allied line were now closer to the city. The city of Ypres was almost completely destroyed. German casualties were recored as 34,933 for the battles, British casualties were 59,279, French casualties were 21,973 and Canadian lost another 5,975.