Abbasid Revolution: The Hashimi rebels under Abu Muslim Khorasani take Merv, capital of the Umayyad province Khorasan, marking the consolidation of the Abbasid revolt.
The Abbasid Revolution, also called the Movement of the Men of the Black Raiment, was the overthrow of the Umayyad Caliphate (661–750 CE), the second of the four major Caliphates in early Islamic history, by the third, the Abbasid Caliphate (750–1517 CE). Coming to power three decades after the death of the Islamic prophet Muhammad and immediately after the Rashidun Caliphate, the Umayyads were an Arab empire ruling over a population which was overwhelmingly non-Arab. Non-Arabs were treated as second-class citizens regardless of whether or not they converted to Islam, and this discontent cutting across faiths and ethnicities ultimately led to the Umayyads' overthrow. The Abbasid family claimed to have descended from al-Abbas, an uncle of Muhammad.
The revolution essentially marked the end of the Arab empire and the beginning of a more inclusive, multiethnic state in the Middle East. Remembered as one of the most well-organized revolutions during its period in history, it reoriented the focus of the Muslim world to the east.