Muslim Conquest of Iraq Begins

In 12 AH (633 CE), Khalid ibn al-Walid led Muslim forces from Yamama into southern Iraq, which was then under Sasanian Persian control. He won a series of battles, including Walaja and Ullais, and took the city of Hira. Al-Muthanna ibn Haritha led Arab tribes already living in the area. These campaigns weakened Persian control over the lower Euphrates and Tigris valleys.