Islamic Abbasid Caliphate (XI: Serica & Romanum)

The Abbasid Caliphate (Arabic: ‎, al-‘Abbāsīyūn) was the third of the Islamic Caliphates of the Islamic Empire. It was ruled by the Abbasid dynasty of caliphs, who built their capital in Mecca after being pushed out of Mesopotamia by the Roman Empire.

It was founded by the descendant of Prophet Muhammad's youngest uncle, Abbas ibn Abd al-Muttalib. It was created in Harran in 750 C.E. and shifted its capital in 762 C.E from Harran to Baghdad. In 1258, Baghdad was sacked by the Mongols, who forced the caliphs to flee to Aegyptus (Roman province of Egypt) for three years. When the Mongol Empire collapsed, the Abbasid family and their followers raised an army and reconquered the Arabian peninsula. The Abbasid caliphate was the center of the Islamic world until its decline in 1744.