 Complete the following phrase:  Khurasan, and the Iranian eastern half of the Caliphate in general, offered fertile ground for the Abbasids missionary activities. Far from the Umayyad metropolitan province of Syria, Khurasan had a distinct identity. It was home to a large Arab settler community, which in turn had resulted in a large number of native converts, as well as intermarriage between Arabs and Iranians. As a frontier province exposed to 