- In 750 the Umayyads were ousted from power by the Abbasid family.
- The other economic engine was Baghdad, capital of the Abbasid dynasty from 762 onward.
- In 1258, the Abbasid dynasty was invaded by the Mongols under Hulagu Khan, the grandson of Genghis Khan.
- It came under the rule of the Abbasid Arabs at the end of the 7th century AD and changed hands intermittently until the establishment of the Turkmen dynasty in 1378.
- This demarcation was reinforced by internal convulsions within the Moslem world culminating in the accession of the Abbasid Caliphate (750), which moved the Islamic capital from Damascus to Baghdad.