Princess Patricia's Canadian Light Infantry, composed largely of British-born former regular soldiers, had gone to Flanders in December 1914 in advance of 1st Canadian Division as part of the British 27th Division. When the Germans launched a major attack into the Ypres Salient over Frezenberg Ridge on 8 May 1915, the PPCLI held the south shoulder of the breach. Despite incurring 392 casualties out of an initial strength of 546, the battalion held on and prevented the Germans from rolling up the British line south towards Armentières, France.

See also First World War.