Abbasid Caliphate. The Abbasid Caliphate (/ÉËbÃ¦sÉªd/ or /ËÃ¦bÉsÉªd/ Arabic: Ù±ÙÙØ®ÙÙØ§ÙÙØ©Ù Ù±ÙÙØ¹ÙØ¨ÙÙØ§Ø³ÙÙÙÙØ©ââ al-KhilÄfatu al-âAbbÄsÄ«yah) was the third of the Islamic caliphates to succeed the Islamic prophet Muhammad. The Abbasid dynasty descended from Muhammad's uncle, Al-Abbas ibn Abd al-Muttalib (566â653 CE), from whom the dynasty takes its name. They ruled as caliphs, for most of their period from their capital in Baghdad in modern-day Iraq, after assuming authority over the Muslim empire from the Umayyads in 750 CE (132 AH).