The battle of Zumail was fought in 633 CE in Mesopotamia (what is now Iraq). It was a major Muslim victory in their conquest of that area. Under cover of night the Arab Muslims attacked the Christian-Arab forces, loyal to the Sasanian Empire, from three different sides. The Christian-Arab forces were unable to withstand the Muslim's surprise attack and soon dispersed but failed to escape from the battlefield and became the victims of a three sided attack by Khalid ibn al-Walid's army. At Zumail nearly the whole Christian Arab army was slaughtered by Khalid's Corps. These battles ended Persian control in Mesopotamia, which finally fell to the Islamic Caliphate.