 By the end of World War I, at least 348 former pupils and teachers of GCI had enlisted, and 48 of those had died while serving overseas.A marble memorial tablet was erected on the wall of the school's main corridor and unveiled on June 4, 1921.Among the military honours awarded to GCI's alumni who served during World War I was a Victoria Cross, the highest award for gallantry awarded in the British army, which was awarded to George Fraser Kerr for a daring raid conducted in broad daylight at Canal-du-Nord during the Hundred Days Offensive.