Alexander & Hellenism (336-146 BC)

From the despised "barbaric" north came the power that would change Greece and half the world: Macedonia. Philip II united the Greek city-states — partly through diplomacy, partly through military force. After his death in 336 BC, his only 20-year-old son took over the legacy.

Alexander the Great (356-323 BC) led perhaps the most remarkable campaign in history in just 13 years. From Macedonia, he conquered the entire Persian Empire, marched through Egypt (where he founded Alexandria), Mesopotamia, Persia, Central Asia to India. When he died at 32 in Babylon — from fever, poison, or alcohol — he had created an empire from Greece to the Indus.

Alexander's true legacy was cultural: the Hellenization of the entire eastern Mediterranean region. Greek language, philosophy, science, and art spread from Egypt to Afghanistan. The Library of Alexandria became the greatest knowledge center of the ancient world. During this era, mathematicians like Euclid and Archimedes, the astronomer Aristarchus (who already proposed a heliocentric worldview!), and the philosopher Epicurus were active.

After Alexander's death, his empire fragmented into Diadochi kingdoms: the Ptolemies in Egypt, the Seleucids in Syria/Persia, and the Antigonids in Macedonia/Greece. These Hellenistic kingdoms flourished culturally but were increasingly politically unstable — which eventually facilitated access for a rising power in the west.