Al-Mansur

Abū Jaʿfar ʿAbd Allāh ibn Muḥammad al-Manṣūr (; Arabic: أبو جعفر عبد الله بن محمد المنصور‎; 714 – 6 October 775) usually known simply as by his laqab al-Manṣūr (المنصور) was the second Abbasid caliph, reigning from 754 to 775, succeeding his brother al-Saffah (r. 750–754). He founded the 'Round City' of Madinat al-Salam, which was to become the core of imperial Baghdad. Modern historians regard al-Mansur as the real founder of the Abbasid Caliphate, one of the largest polities in world history, for his role in stabilizing and institutionalizing the dynasty.