Byzantium Loses Syria and Egypt to the Arab Conquests
A six-day battle at the Yarmouk River hands the Levant to a new Arab caliphate for good
Quick facts
- Key battle
- Yarmouk, August 15-20, 636 CE
- Byzantine commander
- Vahan of Armenia
- Muslim commander
- Khalid ibn al-Walid
- Egypt fell
- 642 CE (Alexandria)
What happened
Just years after exhausting itself in the war against Persia, the Byzantine Empire faced a new opponent in the armies of the Rashidun Caliphate. From August 15 to 20, 636 CE, the Muslim army under Khalid ibn al-Walid fought the Byzantine legions under the field commander Vahan of Armenia at the Battle of Yarmouk in the Jordan valley, and the heavily outnumbered Rashidun forces won decisively. With the main Byzantine army destroyed, cities across Syria including Damascus, Homs, and Jerusalem negotiated surrender, and the provincial capital Caesarea held out until it fell in 641 CE. Arab forces then advanced into Egypt in 639 CE, and Alexandria, the province's capital, came under Muslim control in 642 CE.
Why it matters
Yarmouk permanently shifted control of the Levant from Byzantium to the Caliphate and cost the empire two of its wealthiest and most populous provinces within a few years, shrinking it to a core of Anatolia, the Balkans, and Constantinople itself for the rest of its history.
How we know
The Battle of Yarmouk is documented in the World History Encyclopedia's dedicated article, which names the opposing commanders and the six-day span of the fighting based on early Islamic and Byzantine historical accounts.
Sources
- World History Encyclopedia. Battle of Yarmouk · 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)
- World History Encyclopedia. Early Muslim Conquests (622-656 CE) · 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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