Which empire eventually included arabia mesopotamia persia north africa and parts of spain?

The Abbasid caliphate (750-1258), also called abbasid caliphate, was a Caliph dynasty founded in 750 by Abu l-Abbas, descendant of Abbas, uncle of Muhammad, who took power after eliminating the Umayyad dynasty and moved the capital of Damascus to Baghdad, Baghdad became one of the main centers of world civilization during the caliphate of Haroun al-Rashid, character of the Arabian Nights.

where is the section with the question?