Al-Mansur

Abu Ja'far al-Mansur, second caliph of the Abbasid dynasty, reigned from 754 to 775 and is generally regarded as the true architect of the Abbasid state. Born in 714 into the family descended from al-Abbas, uncle of the Prophet Muhammad, he came to power on the death of his brother al-Saffah, the first caliph of the line, only a few years after the revolution that had overthrown the Umayyads.

His early reign was devoted to eliminating threats to the new dynasty. He defeated the revolt of his uncle Abdallah ibn Ali, a rival claimant, and in 755 had Abu Muslim, the general whose campaigning in Khurasan had brought the Abbasids to power, put to death, removing a commander whose influence the caliph judged too great. In 762 and 763 he crushed the rising of the Alid brothers Muhammad al-Nafs al-Zakiyya and Ibrahim, descendants of Ali who contested the Abbasid claim to leadership of the Muslim community.

Al-Mansur's most enduring act was the foundation of a new capital. In 762 he began building Madinat al-Salam, the City of Peace, on the west bank of the Tigris at the site of the village of Baghdad, by which name the city has always been known. Its famous round plan, with the caliphal palace and mosque at the centre, expressed the new dynasty's authority, and its position on the river trade routes helped it grow rapidly into one of the largest cities in the world and the seat of the caliphate for most of the next five centuries.

Contemporaries remembered al-Mansur as austere and parsimonious, attentive to administration and to the treasury, which he left full. He organised the bureaucracy, relied increasingly on Khurasani troops, and fixed the succession within his own line. He died in 775 while travelling on pilgrimage to Mecca and was succeeded by his son al-Mahdi. Through al-Mahdi he was the grandfather of Harun al-Rashid, and every later Abbasid caliph descended from him. If al-Saffah founded the dynasty, it was al-Mansur who gave it the capital, the institutions, and the ruthlessness by which it endured.