Ancient Greek civilization didn’t collapse in one sudden event. Instead, it went through several periods of decline, each driven by different pressures. Here’s the clear, historian-consensus overview:
1. The Late Bronze Age Collapse (c. 1200–1100 BCE)
This ended the Mycenaean Greek civilization—palace states like Mycenae, Pylos, and Tiryns.
Main causes (multiple, interacting):
• Invasions and migrations
Possibly by groups such as the so-called “Sea Peoples,” or movements of other populations destabilizing the region.
• Internal social and political turmoil
Evidence of widespread palace destruction suggests revolts or internal conflict.
• Systems collapse
Mycenaean society depended on centralized bureaucracy, long-distance trade, and palace economies. When one piece failed (trade, administration, agriculture), the rest unraveled.
• Drought and climate change
Paleoclimate data shows prolonged drought around 1200 BCE, reducing grain harvests and contributing to famine and instability.
• Decline of trade networks
Loss of contact with Egypt, Hatti (Hittites), and Levantine ports weakened the economy.
Result: Greece entered a “Dark Age” (c. 1100–800 BCE) with smaller populations, loss of writing, and simpler political structures.
2. Classical Greek Decline (after 404 BCE)
This refers not to a full collapse but to the weakening of the Greek city-state system.
• The Peloponnesian War
Athens and Sparta’s 27-year conflict (431–404 BCE) devastated both powers:
- Exhausted resources
- Massive casualties
- Damaged farms and infrastructure
- Broke alliances and trust
• Persistent warfare among city-states
After that war, Greeks continued fighting (Theban Wars, Corinthian War), preventing recovery.
• Economic strain
Mercenaries, shifting alliances, and constant mobilizations drained civic wealth.
• Rise of Macedon
Philip II of Macedon exploited Greek disunity and conquered them at the Battle of Chaeronea (338 BCE).
Result: The independence of the Greek poleis ended.
3. The Hellenistic Decline (c. 146 BCE)
After Alexander the Great, his empire fractured into rival kingdoms (Ptolemies, Seleucids, Antigonids), which:
- Fought constant wars
- Suffered internal strife and court intrigues
- Became economically dependent on large armies and mercenaries
Rome’s expansion
Ultimately, Rome defeated Greece in a series of wars.
Greece became the Roman province of Achaea in 146 BCE.
Result: Greek culture survived and spread, but political independence ended.
In summary
There was no single “collapse.” Instead, Greek civilization evolved through three major declines:
- Mycenaean collapse (c. 1200 BCE) → systemic Bronze Age breakdown
- City-state decline (5th–4th centuries BCE) → internal conflict and Macedonian conquest
- Hellenistic decline (2nd century BCE) → absorbed by Rome