Alexander the Great and His Empire

Why this matters

An empire built across three battles, Granicus, Issus, and then Gaugamela, fell apart within years of the king's death, split among his own generals instead of passing to an heir. That speed says something Alexander's conquests alone don't: winning territory and holding it turned out to be two entirely different skills.

The generals who carve up the empire within years of Alexander's death are not outside conquerors, they are the Diadochi he trained and trusted himself. An empire this large falling to insiders instead of enemies says more about succession planning than about the conquest that built it.

From one teacher to another

Every year I ask my students how old Alexander was when he died, and the guess is never close to 32, since he built one of the largest empires in history before some of my seniors' parents would even call him middle-aged. This lesson doesn't let that scale go unexamined: students read Arrian's account of the battle of Gaugamela, then hold it up against the Alexander Mosaic showing the same moment, checking where the ancient text and the ancient image actually agree. By the time they reach the reference guide on Philip II and Aristotle, they've already seen how fast one king's training can turn into an empire, and how fast an empire can fall apart once he's gone.