Canadians often characterize their military history as a march toward nationhood, but in the first eighty years of Confederation they were fighting for the British Empire. War forced Canadians to re-examine their relationship to Britain and to one another. As French Canadians, Indigenous peoples, and those with roots in continental Europe and beyond mobilized for war, their participation challenged the imagined homogeneity of Canada as a British nation. Fighting with the Empire examines the paradox of a national contribution to an imperial war effort, finding middle ground between affirming the emergence of a nation through warfare and equating Canadian nationalism with British imperialism.