What Caused the Bronze Age Collapse?

Nobody knows, and the honest version of that sentence is more interesting than any of the confident ones.

Six explanations are seriously advanced for the end of the Late Bronze Age — Sea Peoples, drought, earthquakes, ironworking, epidemic disease, and general systems collapse — and none has achieved consensus. The reading most scholars now work within is that several of them combined, in a world interconnected enough that shocks propagated.

That is not a fudge. It is what the evidence supports, and the reasons it cannot support more than that are worth understanding, because they are the reasons ancient history is hard in general.

What happened, and to whom

Over roughly fifty years in the late 13th and early 12th centuries BC, the eastern Mediterranean and Near East lost most of its major powers.

The Mycenaean palace economies of the Aegean disintegrated. The Hittite Empire ended. Ugarit, a wealthy Syrian port city whose archives are one of our best windows into the period, was destroyed and not reoccupied. Writing systems fell out of use; long-distance trade contracted; the palace-centred administrative model that had organised production and exchange for centuries stopped.

Not everything went. Egypt of the New Kingdom and Assyria survived in weakened forms. The Phoenician city-states and Elam continued. The conventional date of around 1200 BC traces back to the German historian Arnold Hermann Ludwig Heeren, and it marks a period rather than a moment.

The scale is what makes it a set piece. Individual states fail all the time. A whole system of interlocking states failing within two generations is rare, and it demands an explanation at the level of the system.

The six explanations, and what each one is worth

Invasion by the Sea Peoples

Egyptian records describe seaborne groups attacking the eastern Mediterranean in this period. They are documented, they are real, and they are the oldest explanation on the list.

The difficulty is structural rather than evidential. If the Sea Peoples caused the collapse, what caused the Sea Peoples? Large-scale displacement of populations is itself something that needs explaining, and any answer — famine, drought, upheaval further north — is a cause that would also have been acting on the states they attacked. Invasion works far better as a mechanism inside a larger account than as the account itself.

Drought and climate change

Persistent arid conditions would reduce agricultural yields across a region whose palace economies depended on surplus grain to function at all. This explanation has gained ground as palaeoclimate evidence has improved, and it has the useful property of being a common cause: it acts on everyone at once, which is what the pattern of simultaneous failures requires.

Earthquakes

An "earthquake storm" — a sequence of large seismic events along related fault systems — was once prominent. Recent research suggests earthquakes were not as influential as previously believed.

This is a good illustration of how the field actually moves. The theory was not defeated by a better narrative. It was weakened by closer examination of whether the destruction layers attributed to earthquakes were really earthquakes, really destructions, and really from this period.

Ironworking

The idea that iron weapons overwhelmed bronze-equipped armies is intuitive and has largely fallen out of favour. The chronology runs the wrong way for it: widespread ironworking follows the collapse at least as much as it precedes it, and the collapse itself is a plausible cause of the switch rather than its consequence. When the long-distance tin trade that bronze depended on broke down, iron's advantage was availability rather than superiority.

Epidemic disease

The suggestion of an early, now-extinct strain of bubonic plague appears in the literature. It is difficult to evaluate: disease leaves comparatively little archaeological signature, and the absence of evidence for it is weak evidence of absence.

General systems collapse

The framing that most scholarship has converged on. The proposal is that Late Bronze Age societies had become so intricate — so specialised, so interdependent, so reliant on long trade chains — that once disrupted they could not be reestablished, and each local failure degraded conditions for everyone else.

This is not a cause in the same sense as the others. It is a claim about fragility: about why shocks that a simpler system would have absorbed instead cascaded. That makes it compatible with several of the explanations above rather than a competitor to them, which is precisely why it has become the centre of gravity.

The evidence problem nobody puts on the poster

Here is the part that changes how you should read everything above.

A recurring claim in popular accounts is that a specific large number of cities were destroyed. That claim has been examined directly: a re-examination of the destruction evidence by the archaeologist Jesse Millek, reported in the survey literature, concluded that 61 per cent of the destructions commonly cited had either been misdated, assumed on little evidence, or simply never happened.

Sit with that for a moment. A majority of the specific data points supporting the most dramatic version of the story do not survive re-examination.

That does not mean the collapse is fiction — the Hittite Empire really did end, and Ugarit really was destroyed. It means the texture of the event has been overstated by repetition, and that a general reader encountering a confident account should ask which destructions it is counting and on what basis they were dated. Our article on how historians date events covers the methods that answer that question, and it is the natural companion to this one.