Julius Caesar’s conquest of Gaul, which he undertook largely out of personal ambition, changed the course of European history by bringing the most important center of power north of the Alps under Roman domination. The Gaulish tribes were divided internally over how to deal with the Roman superpower to their south, leaving an opening for Caesar to exploit. By Caesar’s own estimation, the campaigns cost over a million Gaulish lives, but not before a brave last stand by a Gaulish chieftain named Vercingetorix provided a hero the French still admire today. (For related classes about the Celts and the Roman World, see #122 and 215.)