What were the causes of the Abbasid Revolution?

There were several factors behind the fall of the Umayyad Dynasty in the Abbasid Revolution of 750. These include: *Fragmentation of the Umayyad dynasty due to internal feuds *The reliance of Marwan II on the Qaysis (Syrian) faction and his alienation of the Yamani (Yemeni) faction *Opposition to the Umayyads from the Alids (proto-Shiites) and Kharijites