After the assassination of Caliph Ali ibn Abi Talib in 661 CE and the brief caliphate of his son Hasan, Muawiyah ibn Abi Sufyan founded the Umayyad Caliphate, moving the capital from Madinah to Damascus and turning the caliphate into a hereditary dynasty rather than one selected through consultation. Under Umayyad rule, from 661 to 750 CE, the Muslim empire reached its greatest territorial extent up to that time, stretching from the Indus River and Central Asia in the east to the Iberian Peninsula in the west, and encompassing North Africa, the Levant, and Persia. The Umayyads built administrative institutions adapted from Byzantine and Persian models, made Arabic the language of government and coinage, and constructed major monuments including the Dome of the Rock in Jerusalem and the Great Mosque of Damascus. Their rule was also marked by serious internal tension, including the killing of the Prophet's ﷺ grandson Husayn ibn Ali at Karbala in 680 CE, an event of deep and lasting significance especially in Shia Islam, and recurring unrest over questions of legitimate leadership and the treatment of non-Arab Muslim converts. The dynasty was overthrown in 750 CE by the Abbasid movement, though a surviving Umayyad prince later founded a separate emirate in Cordoba, Spain.
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