 The Khurramite leader went into hiding under the protection of a local Christian prince Sahl ibn-Sunbat who later turned him into Afshin.In return for Afshin's achievements, the caliph rewarded him with the governorship of Sind in addition to that of Armenia and Adharbayjan.In 838, al-Mu'tasim decided to launch a major punitive expedition against Byzantium, aiming to capture the two major Byzantine cities of central Asia Minor, Ancyra and Amorium.