The Battle of St. Julien began with the second gas attack by the Germans at Ypres directed at the “Apex” in the line formed as a result of the attack on 22 April. The front line of Apex was held by the 2nd and 3rd Canadian Brigades. At four in the morning on 24 April 1915 a German artillery bombardment began and simultaneously they released chlorine gas in the direction of the lines held by 1st Canadian Division. The gas was centred on the junction of 2nd and 3rd Brigades, falling most heavily on the 8th and 15th Battalions. Even under the strenuous conditions caused by the gas, the Canadian front line battalions were able to momentarily halt the initial waves of Germans. Heroic fighting by those units allowed the Canadian brigades to withdraw to positions along the Gravenstafel Ridge.
The Germans launched a simultaneous attack between Kitcheners Wood and Keerselare. Despite their best efforts, the Canadian front-line units only gave some pause to the German attack. Almost overrun, they withdrew to positions along the Gravenstafel Ridge while several British battalions arrived in the Canadian sector to help reinforce the lines. Despite severe confusion and conflicting messages to and from commanders, new defensive positions were gradually established. Only the 2nd Brigade, on the far right of the Canadian line, still held part of its original front line at the end of the day on the 24th of April.
In the early morning of the 25th, a British brigade launched a counter-attack in the area between Kitcheners Wood and St-Julien. Even if objectives were not reached, it blocked a gap in the line and caused the Germans to commit troops that were supposed to conduct an attack of their own in this area. This German attack at Kitcheners Wood was supposed to be coordinated with an attack on the 2nd Canadian Brigade in the Apex in the line North of Gravenstafel. Canadian units held the line for most of the day but by evening, the German attack forced the Canadians back behind Gravenstafel. The remaining troops of the Brigade were relieved in place by a British unit. The remainder of the Canadian Division was gradually relieved in place by British units with most Canadians out of the line on the 26th of April.
That brought an end to the fighting for the infantry battalions of the 1st Canadian Division in the Battle of St-Julien, although British units continued to fight in the area for several more days.
St Julien was captured on the first day of the 3rd Battle of Ypres, 31 July 1917, by troops of the 39th Division and took 222 prisoners, supported by two tanks, which then silenced an artillery battery nearby. On the left of the division, the 117th Brigade rushed three pillboxes at Kansas Cross, killed the machine-gunners and took several prisoners. Two tanks advanced on the Alberta strong point, flattened uncut wire and kept the garrison under cover as the infantry advanced. At the first objective, the infantry pausing for an hour and then moved downhill, behind a smoke and shrapnel barrage, to the Steenbeek, one of the muddiest parts of the battlefield. By 8:00 a.m. both brigades had reached the final objective and were digging in on the east side of the Steenbeek. The village passed into German hands again on 27 April 1918, but was finally retaken by the Belgian Army on 28 September.