Alexander the Great invaded Afghanistan in 330 BCE, pursuing the fleeing Persian emperor Darius III after destroying the Achaemenid Empire's core territories. The region—ancient Bactria and Sogdiana—proved his most brutal challenge. Mountain fortresses, guerrilla warfare, and fierce local resistance forced Alexander into a grinding three-year campaign unlike his swift conquests elsewhere. He faced constant ambushes in narrow passes, revolts that reignited after seeming victory, and enemies who r