On the night of 28 February 1915, 100 men of the Princess Patricia's Canadian Light Infantry staged the first trench raid of the war near Ypres, Belgium. They destroyed 30 yards of German trenches and experienced casualties of 5 killed and 11 wounded. At that time, the British, French, and Germans had never conducted any small-scale operations between major offensive operations.
Lieutenant-Colonel Victor Odlum, commander of the 7th Battalion, 1st Canadian Division, refined the technique of trench raiding. In November 1915, Odlum conducted a carefully planned raid with 170 volunteers. The Canadian attack surprised the German defenders, and they took several prisoners while suffering only two casualties. The preferred weapons of the Canadian trench raiders were hand grenades and Lewis light machine guns. Although the Lewis machine gun had a limited ammunition capacity, it was a lightweight weapon that could be easily used in hit-and-run forays.
By the end of the year, Canadians had gained a reputation as experts in trench raiding, and Marshal Joffre, the Allied Commander-in-Chief, sent French officers to Canadian headquarters to learn these techniques. Both sides adopted trench raids as standard practice on the Western Front. They were used to gather valuable information on enemy defences before launching an offensive operation.