Caliph Harun al-Rashid, father of al-Ma'mun and…
820 CE
Caliph Harun al-Rashid, father of al-Ma'mun and al-Amin, had in 802 ordered that al-Amin succeed him and al-Ma'mun serve as governor of Khurasan and as caliph after the death of al-Amin.
Al-Ma'mun was reportedly the older of the two brothers, but his mother was a Persian woman while al-Amin's mother was a member of the reigning Abbasid family.
After al-Rashid's death in 809, the relationship between the two brothers had deteriorated.
In response to al-Ma'mun's moves toward independence, al-Amin had declared his own son Musa to be his heir.
This violation of al-Rashid's testament had led to a civil war in which al-Ma'mun's newly recruited Khurasani troops, led by Tahir bin Husain, a former slave, had defeated al-Amin's armies and laid siege to Baghdad.
In 813, al-Amin had been beheaded and al-Ma'mun recognized as caliph throughout the empire.
There had been disturbances in Iraq during the first several years of al-Ma'mun's reign, while the caliph was in Merv in Khurasan.
On November 13, 815, Muhammad Jafar had been acclaimed caliph in Mecca.
He had been defeated, however and abdicated asserting that he'd only become caliph on news that al-Ma'mun had died.
Lawlessness in Baghdad has led to the formation of neighborhood watches.
When in 817 al-Ma'mun had named as his heir Ali al-Rida, or Imam Reza, the Seventh descendent of Muhammad—a political move designed to please the Persians, since most of Iran is sympathetic to the Hashemites—Baghdad residents had not accepted this, and instead given their allegiance to Ibrahim ibn al-Mahdi.
His forces had fought al-Ma'mun's as well as Kharijites (a general term embracing various Muslims who, while initially supporting the caliphate of the fourth Caliph Ali, later rejected him) and arrested the neighborhood watch commander Sahl ibn Salamah.
After Ali al-Rida informed al-Ma'mun of happenings in Baghdad, al-Ma'mun set out for the city.
Following the death, in 818 at Tus, of Ali al-Rida, which many attributed to al-Ma'mun, a great revolt had taken place in Khorasan, Persia.
Al-Ma’mun, weeping and mourning for Ali al-Rida, had tried to show himself innocent of the crime, but to little avail.
Upon his arrival in Baghdad on August 11, 819, al-Ma'mun had worn green, but a week later had abandoned his policy of reconciliation with the descendants of 'Ali, which he had symbolized by reinstating the traditional black 'Abbasid flag, although he has not abandoned hope of attaining the same goal by means of a more circuitous path.
He had already, at Merv, evidenced his sympathy for the representatives of the Mu'tazili movement, those supporters of Islam who have adopted rationalist methods and borrowed from the works of ancient Greek or Hellenistic philosophers the modes of reasoning that seems to them best-suited for combating the influence of such doctrines as Manichaeism, the dualistic religion that had been founded in Iran in the third century.
During the following years, al-Ma'mun's reign will be marked by tolerance and the development of a philosophical form.