Abu Muslim was a general of Persian origin who acted as the primary agent (da'i) for the Abbasid family in the eastern province of Khorasan. He successfully united diverse groupsโPersian converts (Mawali), disgruntled Arab tribes, and Shiite sympathizersโunder the black banners of the Abbasids.
In 747, he openly proclaimed the revolution in Merv. His military leadership was instrumental in the series of victories that led to the fall of the Umayyad dynasty. Despite his vital role, he was later seen as a threat by the second Abbasid Caliph, al-Mansur, who had him executed in 755.