What was the centre of Abbasid uprising? Why did it take place? Give reasons.

Explanation

The Umayyad dynasty was brought down by a well-organised movement called .Dawa.. It was then replaced by Abbasids in 750. The main centre of their uprising was the distant region of Khurasan.
Main Reasons :
(i) Mobilisation of the mixed Irannian population for various reasons.
(ii) The Umayyad projected themselves rested on force and loyalty of Syrian troops which resented the Arab soldiers.
(iii) The Aab civilians disliked the Umayyad regime for failure of unfulfill their promises.
(iv) Umayyad regime was portrayed as an evil by the Abbasids.