Kayqubad I
The battle took place in Yassıçemen, a location west of Erzincan. Jalal ad-Din tried to attack before the merging of the Seljuk and Ayyubid armies, but it was too late, as the Ayyubids had already sent a reinforcement of 10,000 to the Seljuks. The commander of the Seljuk-Ayyubid army was the Seljuk sultan Ala-ad Din Kayqubad I. The battle continued for three days. An able commander, Jalal ad-Din almost defeated the Seljuk-Ayyubid alliance in the first day. But at the end of the three days Jalal ad-Din’s forces were defeated.