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BATTLE // May 1, 0633

Battle of Ullais

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Overview

The Battle of Ullais was fought between the forces of the Rashidun Caliphate and the Sasanian Persian Empire in the middle of June 633 AD in Iraq, and is sometimes referred to as the Battle of Blood River since, as a result of the battle, there were enormous amounts of Persian Sasanian and Arab Christian casualties.

Overview adapted from Wikipedia, licensed under CC BY-SA 4.0.

Significance

The Battle of Ullais, fought in June 633 in Iraq, was one of the early engagements of the Rashidun Caliphate's push into Sasanian Persia. The scale of recorded casualties — 70,000 on the Sasanian side against 2,000 for the Rashidun forces commanded by Khalid ibn al-Walid and Al-Muthanna ibn Haritha — indicates a decisive Rashidun victory, though the battle's outcome is not formally recorded in the structured record. The engagement is sometimes called the Battle of Blood River, a name that reflects the reported magnitude of Sasanian and Arab Christian losses. As an early action in the Muslim conquest of Persia, Ullais contributed to the erosion of Sasanian military capacity in the Iraqi theater, forming part of the initial Rashidun offensive that would ultimately bring the Sasanian Empire to collapse over the following two decades.

Forces & casualties

Troop strength

  • Rashidun Caliphate18,000
    medium
  • Sasanian Empire70,000
    medium

Sasanian Empire fielded a 3.9 : 1 numerical advantage

Casualties

  • Rashidun Caliphate2,000
    medium11% loss rate
  • Sasanian Empire70,000
    medium100% loss rate

Commanders (2)

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6 sibling battles · 0 factions

Last verified July 2026
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