2. Historical development: Alexander the Great: Conquest & Empire

Historical developments and consequences

Philip II of Macedon was assassinated in 336 BCE, leaving his son Alexander, then about twenty, a kingdom with a reorganized army and a plan to invade the Achaemenid Persian Empire. Alexander first secured Macedonian authority in Greece. When Thebes revolted in 335 BCE, Macedonian forces destroyed much of the city and enslaved many inhabitants; this violence preceded the Persian campaign and served as a warning to other Greek cities.

Philip II of Macedon reorganized the army before his assassination in 336 BCE. Alexander III succeeded him and took personal command of campaigns against the Achaemenid Empire. After Darius III was defeated, Alexander appointed satraps and military governors; his death in 323 BCE left no accepted adult successor.

Conquest and administrative continuity

Alexander crossed into Asia Minor in 334 BCE. Victories at the Granicus River (334 BCE), Issus (333 BCE), and Gaugamela (331 BCE) undermined the authority of Darius III. Alexander entered Egypt in 332 BCE and founded Alexandria in 331 BCE. He captured major Persian royal centers, including Babylon, Susa, and Persepolis, but conquest did not eliminate the need for local administration. Satraps, regional tax collection, and established agricultural production remained essential to maintaining armies and governing populations.

Costs, resistance, and succession

Campaigning extended eastward through Bactria and Sogdiana, where resistance required prolonged military operations. Alexander's troops refused to advance farther east at the Hyphasis River in 326 BCE. His return through the Gedrosian desert cost many lives. Alexander died in Babylon in 323 BCE without an uncontested adult successor. Wars among his commanders produced competing Hellenistic kingdoms rather than a durable single empire.

Consequences extending beyond the conquest

Greek became an important administrative and cultural language across several successor kingdoms, while Egyptian, Mesopotamian, and other local traditions continued. Alexandria developed into a major center of trade and scholarship under the Ptolemies. The successor states inherited territory, tax obligations, military settlements, and disputes over dynastic rule; these institutions and rivalries shaped eastern Mediterranean politics for centuries.