John Connelly explores the long-term consequences of Germany’s emergence as a nation that was at once imperial and ethnic—a country that occupied a huge space in Central Europe and sought to make millions of diverse human beings into ethnic co-nationals. Connelly reaches back to just after the fall of Rome but ultimately seeks to account for the disruptive role the more recent “German Question” played in causing, as German president Frank-Walter Steinmeier has said, “a unique break with civilization.”