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622 to 628 CEReputable source · 2 sourcesWell documented

Heraclius Defeats Persia in the Last Great War of Antiquity

After Sasanian armies overrun the east, Heraclius rebuilds the army and reverses the empire's near-total collapse

On the timeline · around 622 to 628 CE · Justinian, Reconquest, and CrisisJustinian, Reconquest, and CrisisHeraclius Defeats Persia in the Last Great War of Antiquity550 CE575 CE600 CE625 CE650 CE675 CE700 CE

Quick facts

Byzantine emperor
Heraclius (r. 610-641 CE)
Persian king
Khosrow II
War
602 to 628 CE
Outcome
True Cross returned to Jerusalem

What happened

Heraclius became emperor in October 610 CE after leading a fleet from Carthage to overthrow the tyrant Phokas, inheriting an empire already reduced to half its former size and effectively bankrupt. The Sasanian Persian king Khosrow II, who had declared war ostensibly to avenge Phokas's victim Maurice, spent the years from 602 to 622 CE conquering the Levant, parts of Anatolia, and Egypt for the first time in the war. Heraclius spent years rebuilding Byzantine finances and forces before launching counter-offensives from 622 to 626 CE that pushed into Persian territory itself. His campaigns, combined with the defection of the Persian general Shahrbaraz after Heraclius revealed Khosrow's secret order for his death, forced the Persians onto the defensive and ended the war by 628 CE with the return of the True Cross, captured by the Persians, to Jerusalem.

Why it matters

The victory saved the empire from collapse at its lowest point and let Heraclius found a dynasty that stabilized Byzantine rule, but both empires emerged from this two-decade war exhausted just as Arab armies began their conquests in the following decade, leaving neither Byzantium nor Persia able to mount an effective defense.

How we know

The World History Encyclopedia's biography of Heraclius traces his succession, the war's course, and its cost, based on Byzantine chronicle sources describing the campaigns against Khosrow II.

Sources

  • World History Encyclopedia. Heraclius · Reputable sourceworldhistory.org · The domain "worldhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
  • Livius.org (Jona Lendering). Heraclius · Reputable sourcelivius.org · The domain "livius.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)

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Heraclius Defeats Persia in the Last Great War of Antiquity · The Byzantine Empire · SourcedStory