Last updated August 6, 2025

Major Civilizational Collapses: Key Periods and Causes

Understanding the Causes of Civilizational Collapse

Human history has been marked by several major collapses of civilizations, sometimes partial (Western Roman Empire), sometimes reversible (Classic Maya Civilization), and often irreversible (Easter Island Civilization). These complex phenomena generally result from the interaction of multiple environmental factors, i.e., abrupt or gradual disruptions in the political, social, economic, or cultural continuity of a complex society.

Probable Causes of Civilizational Collapse

Environmental Causes: Abrupt climate changes (droughts, cooling, floods), massive deforestation, soil depletion, or disruption of hydric cycles. These phenomena reduce agricultural productivity and ecological resilience.
Economic Causes: Disruption of trade networks, scarcity of key resources, monetary decline, collapse of redistributive infrastructures essential for maintaining complex societies.
Social and Political Causes: Corruption, dynastic instability, popular revolts, civil wars, institutional rigidity, and inability to reform power structures in the face of crises.
Demographic Causes: Relative overpopulation, mass migrations, imbalances between urban centers and peripheries, or rapid population decline weakening society.
Health Causes: Devastating pandemics, collapse of public health linked to famines or malnutrition, loss of medical knowledge.
Cultural Causes: Symbolic crisis, loss of legitimacy of religious or ideological institutions, ideological rigidity preventing adaptation to economic or environmental changes.
Technological Causes: Loss or stagnation of technical knowledge, dependence on unsustainable complex infrastructures, inadequacy of technologies in the face of new environmental challenges.
Geopolitical/Exogenous Causes: Invasions, repeated military pressures, prolonged wars, domination or colonization by foreign powers causing destabilization and fall of political centers.
Systemic Causes (Excessive Complexity): Increasing marginal cost of social and administrative complexity, energy and organizational overload, making society vulnerable to external and internal shocks.

Sources: Joseph Tainter, The Collapse of Complex Societies (1988), Jared Diamond, Collapse (2005), Eric H. Cline, 1177 B.C. (2014).

Precursor Signs of Collapse

The collapse of a civilization never occurs without precursor signs. These indicators, often visible decades or even centuries beforehand, take various forms but converge towards a dynamic of systemic weakening. Archaeologists, historians, and climatologists identify a set of recurring factors:

Environmental Degradation: deforestation, soil erosion, salinization, overexploitation of water or agricultural resources weaken the productive base.
Abrupt Climate Changes: prolonged drought episodes (as with the Mayans or Akkadians) or climatic cooling (Viking Greenland) reduce resilience.
Unsustainable Demographic Growth: an excess of population relative to available resources leads to famines, social tensions, and weakens political structures.
Institutional Rigidity: elites often refuse to reform structures that have become inadequate (cases of Rome, Easter Island, or the Vikings of Greenland).
Political Fragmentation or Civil War: internal conflicts often precede external invasions or the collapse of trade (e.g., Inca Empire, Khmer Empire).
Loss of Ideological or Religious Legitimacy: when symbolic structures no longer respond to the crises experienced by the population, power collapses from within (Mycenians, Hittites).
Collapse of Long-Distance Trade: the disintegration of exchange networks (as at the end of the Bronze Age) causes a local retreat often fatal to large urban centers.

These signs do not guarantee a collapse, but their conjunction increases the probability of a tipping point. Their study today helps to better understand contemporary vulnerabilities, particularly in the context of the Anthropocene.

Table of Major Collapses

The following table summarizes several emblematic cases of civilizational collapse throughout human history. Each collapse is presented with its peak period, location, date of decline, and probable causes.

Historical Civilization Collapses: Summary
Civilization	Period	Region	Date of Collapse	Duration of Decline	Probable Causes	Specific Remarks
Indus Valley Civilization (Harappa)	c. 2600–1900 BCE	Pakistan, northwest India	c. 1900 BCE	200–300 years	Climate changes, weakening of trade, floods	No traces of war or brutal conquest
Akkadian Empire	c. 2334–2154 BCE	Mesopotamia	c. 2150 BCE	50–80 years	Severe aridification, internal conflicts, invasion by the Guti	First multiethnic empire
Hittite Empire	c. 1600–1178 BCE	Anatolia (Turkey)	c. 1178 BCE	20–50 years	Invasions (Sea Peoples), drought, dynastic conflicts	Sudden end of Hattusa
Mycenaean Civilization	c. 1600–1100 BCE	Greece	c. 1100 BCE	100–150 years	Earthquakes, wars, famines, invasions	Beginning of the "Greek Dark Ages"
New Kingdom of Egypt	c. 1550–1070 BCE	Egypt	c. 1070 BCE	150–200 years	Internal troubles, decline of the Nile, economic instability, invasions	Significant political fragmentation
Assyrian Empire	c. 900–612 BCE	Northern Mesopotamia	612 BCE	20–40 years	Internal revolts, enemy coalition, economic exhaustion	Capital Nineveh destroyed
Olmec Civilization	c. 1200–400 BCE	Gulf of Mexico	c. 400 BCE	100–200 years	Climate changes, population movements	Precursors to the Mayans
Western Roman Empire	27 BCE – 476 CE	Western Europe	476 CE	200–250 years	Economic crisis, political instability, barbarian invasions	Transition to the Middle Ages
Classic Maya Civilization	c. 250–900 CE	Mesoamerica	c. 900 CE	100–200 years	Droughts, overpopulation, wars, local ecological collapse	Major southern cities abandoned
Tiwanaku Empire	c. 500–1000 CE	Andes (Bolivia, Peru)	c. 1000 CE	50–100 years	Prolonged drought, agricultural decline, regional instabilities	Predecessor to the Incas
Khmer Empire (Angkor)	c. 802–1431 CE	Cambodia	1431 CE	100–150 years	War with Siam, hydraulic crisis, political instability	Angkor Wat gradually abandoned
Easter Island Civilization	c. 1200–1600 CE	Easter Island (Rapa Nui)	c. 1600–1700 CE	100–150 years	Deforestation, ecological collapse, internal conflicts, isolation	Emblematic case of overconsumption
Inca Empire	c. 1438–1533 CE	Andes (Peru, Bolivia, Ecuador)	1533 CE	10–20 years	Spanish conquest, civil war, epidemics	Very rapid fall to Pizarro
Aztec Empire	c. 1428–1521 CE	Central Mexico	1521 CE	5–10 years	Spanish conquest, diseases, anti-Aztec indigenous alliances	Spectacular end of Tenochtitlan
Viking Civilization of Greenland	c. 980–1450 CE	Greenland	c. 1450 CE	100–150 years	Little Ice Age, isolation, social rigidity	Refusal to adapt to the Inuit climate