Prompt: , the strong man in establishing the Abbasid state, the son of Muhammad bin Ali, the founder of the Abbasid call, and the mastermind of the efforts of his brother Abu al-Abbas, the murderer, the first Abbasid caliph. By the year 132 AH, in which the people of Kufa pledged allegiance to Abu Abbas Caliph, the lands that owed Islam extended from Andalusia to Central Asia, and most historians believe that the failure of the Umayyads to deal with the ethnic and cultural diversity represented by this expansion was the basis for their downfall. Their state, and then the emergence of the Abbasid call, which relied on the strong opposition existing in the cities of Khorasan to Umayyad rule