later established himself in the city of Tabriz. There he worked under another Arab warlord, Muhammad ibn Rawwad Azdi for two years, until he reached adulthood and left for his village, Bilalabad. There Babak encountered a wealthy and influential landlord named Javidhan, who was reportedly impressed with the latters cleverness, and as result recruited him into his service. Unlike the previous men Babak had served, Javidhan was a local Iranian, and the leader of one of the two Khurramite movements in Azerbaijan. The leader of the other Khurramite movement was a certain Abu Imran, who often clashed with Javidhans forces. During one of the clashes, Abu Imran was defeated and killed, whilst Javidhan was mortally wounded, dying three days later. Javidhan was succeeded by Babak, who had already converted to Khurramism under the latters service. It was most probably during this period that Babak changed his name from al-Hasan to Babak. Movement In 755, Abu Muslim was murdered. Although he had helped the Abbasids to defeat the former Caliphs, the Umayyad dynasty, the ruling Caliph had given the order to kill him, probably because of his increasing popularity among Iranians and non-Muslims. This incident led to many revolts, mostly by angry Khurramiyyah (Khorram-Dinān) and some Zoroastrians. This, in turn, forced the Caliphs to use more violence against the Iranian population in order to keep the eastern provinces under control. The constant revolts did not come to an end in the following decades, and the Iranian population of the Caliphate was constantly being oppressed. Babak joined the Khurramiyyah (Khorram-Dinān). The story of joining the Khorrami movement is being told in Waqed's account, in summary, as follows: Under the direction of his mentor Javidhan, a leader of one of the sects of the Khorramdin, Babak's knowledge of history, geography, and the latest battle tactics strengthened his position as a favorite candidate for commander during the early wars against the Arab occupiers. Bābak was a highly spiritual person who respected his Zoroastrian heritage. He made every possible effort to bring Iranians together and also with leaders such as Maziar to form a united front against the Arab Caliph. According to the medieval historian, Ibn Esfandyar, who composed the book Tarikh-e Tabaristan (History of Tabaristan), Maziar said: However, one of the most dramatic periods in the history of Iran was set under Bābak's leadership between 816–837. During these most crucial years, they not only