The Battle of al-Qadisiyyah
An Arab army defeats a larger Sassanid force near the Euphrates and opens the road into the Persian heartland
Quick facts
- Sassanid commander
- Rostam (killed in battle)
- Traditional date
- 636 or 637 CE
- Alternate scholarly dating
- 634-635 CE, per numismatic evidence
- Lost symbol
- The Derafsh-e Kaviani, royal standard
What happened
In the mid-630s CE, an invading Arab Muslim army confronted a larger Sassanid force near al-Qadisiyyah, close to al-Hirah in present-day Iraq, in a multi-day engagement traditionally dated to 636 or 637 CE, though the Encyclopaedia Iranica notes that some modern scholars, citing numismatic evidence pointing to a serious blow to Sassanid administration as early as 634 or 635 CE, argue for an earlier chronology. The Sassanid commander Rostam was killed in the fighting, along with the loss of the Sassanid royal standard known as the Derafsh-e Kaviani, a banner of deep symbolic importance to Persian kingship. The Arab victory broke organized Sassanid resistance in Mesopotamia and opened the road toward the Sassanid capital at Ctesiphon, which fell soon after.
Why it matters
Al-Qadisiyyah is treated by both Arab and Persian historical traditions as the decisive battle that broke Sassanid Iraq and made the subsequent Arab conquest of the Iranian plateau possible, even though scattered Persian resistance would continue for another decade.
How we know
Early Islamic historical tradition, compiled a century or more after the events from earlier oral and written sources, provides the fullest narrative; the exact date remains genuinely disputed among modern scholars using different categories of evidence, including coin dating.
Sources
- Encyclopaedia Iranica. QADESIYA, BATTLE OF · General sourceiranicaonline.org · Cited as a "reference" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- Encyclopaedia Iranica. ARAB ii. Arab conquest of Iran · General sourceiranicaonline.org · Cited as a "reference" source (no stronger domain match).
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