Of Canada’s long military history, Vimy is the one battle that most Canadians will know. Some will be familiar with Passchendaele, D-Day or the disasters at Hong Kong and Dieppe. Canadians should know the Hundred Days because the battles that constitute that offensive were almost certainly the most important victories ever won by Canadian soldiers. This article analyses the various reasons for the stunning Canadian successes of that war-winning offensive: chiefly the Canadian experience and doctrine; the state of the enemy and the Allies; artillery and counter-battery fire (the most important tactical arm); and logistics and administration. Ultimately, as the Hundred Days’ spearhead with replenishable manpower and with near unmatched firepower, experience, ingenuity, organisation, leadership, reputation and material resources, the Canadian Corps was the decisive war-winning formation on the Western Front.