The Byzantine-Sassanid War and the Loss of the True Cross
Khosrow II nearly conquers the Byzantine Empire, takes Jerusalem and its holiest relic, and then loses everything in six years of Heraclius's counterattack
Quick facts
- Persian king
- Khosrow II (deposed 628 CE)
- Byzantine emperor
- Heraclius
- Jerusalem captured
- 614 CE
- War ends
- 628 CE, True Cross returned
What happened
Khosrow II launched an invasion of Byzantine territory in 602 or 604 CE, framed officially as revenge for the murder of the Byzantine emperor Maurice, his own benefactor, by the usurper Phocas. Persian forces under the general Shahrbaraz took Antioch in 612 CE and Damascus in 613, then advanced on Jerusalem the following year. According to livius.org's summary of the ancient sources, the Persians captured Jerusalem in 614 CE and carried off the True Cross, the relic Christians believed was the actual cross of the crucifixion, an event that caused panic and outrage across the Byzantine world. Persian forces went on to occupy Egypt as well, at their furthest extent controlling more territory than any Sassanid king before them. But the new Byzantine emperor Heraclius, who had overthrown Phocas in 610 CE, launched a sustained counteroffensive from 622 to 626 CE and eventually defeated a major Persian army near the ruins of ancient Nineveh. Khosrow II was overthrown by his own army in a palace coup in March 628 CE and replaced by his son Kavad II, who immediately sued for peace, returning all Byzantine territory, prisoners, and the True Cross itself.
Why it matters
This was the last and most destructive of the centuries-long wars between Rome or Byzantium and Persia, and it exhausted both empires so thoroughly that neither had the resources to resist the Arab armies that erupted out of Arabia within a decade of the peace treaty.
How we know
Byzantine chroniclers including Theophanes and Theophylact Simocatta, alongside the Armenian history attributed to Sebeos, provide independent narrative accounts from the winning side; Sassanid court records for this period did not survive the empire's own collapse a generation later.
Sources
- Livius.org (Jona Lendering). Khusrau II the Victorious · 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)
- World History Encyclopedia. Khosrow II · 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)
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