429 BC

Plague of Athens

The Plague of Athens continues into its second year

Thucydides said the wider death toll could not be determined. The familiar "more than a third of Athens" is not a figure any ancient source supplies.

Not an outbreak, and not a return

No single outbreak can be dated to a day in 429 BCE. Thucydides says the epidemic first struck Athens in summer 430 and that its first visitation lasted two years — so 429 is its continuation, not its beginning.

Nor was it a fresh return. Thucydides identifies the second attack as coming in winter 427/426, after an abatement.

The disease took hold first in Piraeus and then reached the upper city. Thucydides records where it appeared, not how it arrived; the claim that infected ship passengers carried it in is speculation.

The one-third figure has no source

Thucydides gives partial military losses — at least 4,400 enrolled hoplites and 300 cavalry across the epidemic's recorded visitations — but says the number among the wider population could not be determined.

There is no surviving census of Athens, and demographic reconstructions are highly uncertain, so a percentage of the whole population cannot be presented as a contemporary count.

"Plague" here translates a general word for epidemic disease. It is not a diagnosis of bubonic plague, and proposed modern identifications remain contested.

What the eyewitness did describe

Thucydides, who caught the disease and survived, describes crowded temporary lodgings, abandoned sufferers, corpses in streets and temples, and families placing their dead on pyres other households had prepared. Physicians, approaching the sick most often, were among the earliest victims.

A mass burial near the Kerameikos held about 150 skeletons. It is dated broadly to roughly 430–426 BCE and linked to the epidemic by interpretation, not assigned to 429.

Pericles died in 429 after a lingering illness; it is Plutarch, writing much later, who most explicitly identifies that illness with the epidemic.

Sources

Researched 24 Aug 2026 6 sources not yet audited Date disputed

How this was checked

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Date disputed. Sources disagree about when this happened.

What the sources leave uncertain

The listed claim that more than one-third of Athens died is not a securely documented ancient statistic. Thucydides gives partial military losses but says the number among the wider population could not be determined.
Calling 429 a separate return is misleading: Thucydides describes the first visitation as lasting two years and identifies winter 427/426 as the second attack after an abatement.
“Plague” translates a general word for epidemic disease, not a diagnosis of bubonic plague. Proposed diagnoses remain contested.
The Kerameikos burial is dated broadly to approximately 430–426 BCE and associated with the epidemic from its date and unusual burial conditions; it cannot be assigned specifically to 429.