Born in Montreal, «Pete» Illsley interrupted in 1915 his studies in architecture at McGill Universty to enlist in the army during WWI. In 1917, he became air observer, flying R.E.8s in France. He then qualified as pilot and was posted back to France in the spring of 1918 to fly R.E.8s with No.52 Squadron (at the time severely battled by the German air force). Most French and British troops on the Western Front were then commanded by French General Foch. On May 30, 1918, Illsley’s R.E.8 was hit and his observer seriously wounded. Illsley managed to force land under enemy shell fire and got his comrade to hospital. On June 16, he was mentionned in French dispatches (à l’Ordre de l’Aéronautique de l’Armée), with the citation that Lieutenant Illsley «in spite of frequent ennemy patrols, stayed in contact with the infantry, dropped bombs on ennemy reinforcements while under heavy gun fire, and brought back to Command important information». Three days later, he received the French Croix de guerre from the hands of General Foch himself. Back to civilian life, Illsley remained involved with military aviation throughout his life, especially with the youngsters. On April 9, 1941, as WWII was raging, he co-founded (with Air Marshall William A. «Billy» Bishop and George B. Foster) the Air Cadet League of Canada. On September 24, 1941, Illsley formed the very first squadron (No.1 Westmount), which he commanded until 1948.
Back to civilian life, Illsley remained involved with military aviation throughout his life, especially with the youngsters. On April 9, 1941, as WWII was raging, he co-founded (with Air Marshall William A. «Billy» Bishop and George B. Foster) the Air Cadet League of Canada.
At the end of the war, 374 squadrons had been raised. During this period, Illsley donated to the League a trophy (today the H.P. Illsley Trophy) awarded to the best drums and bugles band. In 1953, while Vice-President of the Air Cadet League of Canada, he was awarded the Queen’s Coronation Medal. In 1958, he was elected National President of the League, remaining afterward on the Advisory Board until his death three decades later. A well-known architect, his firm designed in the 1950’s the original plans of the Dorval terminal (today Trudeau airport). Among his other architectural projects were the Montreal Forum, Manoir Richelieu, Château Laurier and St.Mary’s hospital in Montreal.