Editing Al-Ma'mun (section)

==Internal strife==
===Sahl ibn Salama al-Ansari===
There were disturbances in [[Iraq]] during the first several years of al-Maʾmūn's reign, while the caliph was in [[Merv]] (near present-day [[Mary, Turkmenistan]]). On 13 November 815, [[Muhammad ibn Ja'far al-Sadiq (al-Dibaj)]] claimed the Caliphate for himself in [[Mecca]]. He was defeated and he quickly abdicated asserting that he had only become caliph on news that al-Ma'mun had died. Lawlessness in [[Baghdad]] led to the formation of neighborhood watches with religious inspiration,  with two notable leaders being Khalid al-Daryush and Sahl ibn Salama al-Ansari.  Sahl adopted the slogan, ''la ta'a lil- makhluq fi ma'siyat al-khaliq'', or 'no obedience to the creature in disobedience of the Creator'<ref name="Lapidus-1975-375"/> (originally a Kharijite slogan),<ref name="Lapidus-1975-376"/> alluding to what he saw as "the conflict ... between God's will and Caliphal authority". "Most" of the leadership of this vigilante movement came from the ''sulaahd'' ("men of good will of the neighborhoods and blocks") and from "popular preachers" (as both Khalid al-Daryush and Sahl ibn Salama al-Ansari were); its followers were called the '' 'amma'', (the common people).<ref name="Lapidus-1975-375">{{cite journal|last1=Lapidus|first1=Ira M.|date=1975|title=Separation of state and religion in early Islamic society |url=https://www.jstor.org/stable/162750 |journal=International Journal of Middle East Studies |volume=6|pages=375|doi=10.1017/S0020743800025344|jstor=162750|s2cid=162409061 |access-date=2 July 2021}}</ref>  The volunteers of the movement were known as  ''mutawwi'a'', which was the same name given to "volunteers for frontier duty and for the holy war against Byzantium".<ref name="Lapidus-1975-376">{{cite journal|last1=Lapidus|first1=Ira M.|date=1975|title=Separation of state and religion in early Islamic society |url=https://www.jstor.org/stable/162750 |journal=International Journal of Middle East Studies |volume=6|page=376|doi=10.1017/S0020743800025344|jstor=162750|s2cid=162409061 |access-date=2 July 2021}}</ref>
Sahl's and movement influence was such that military chiefs first "delayed capitulation to al-Ma'mun" and  adopted  Sahl's religious "formula" until they became alarmed at his power and combined to crush him in 817–18 CE.<ref name="Lapidus-1975-372-3">{{cite journal|last1=Lapidus|first1=Ira M.|date=1975|title=Separation of state and religion in early Islamic society|url=https://www.jstor.org/stable/162750|journal=International Journal of Middle East Studies|volume=6|pages=363–385|doi=10.1017/S0020743800025344|jstor=162750|s2cid=162409061 |access-date=2 July 2021}}</ref>

===Imam al-Rida===
In A.H. 201 (817 AD) al-Ma'mun named [[Ali ar-Rida]] (the sixth-generation descendant of [[Ali]] and the eighth Shia Imam) as his heir as caliph. This move may have been made to appease Shi'ite opinion in Iraq and "reconcile the 'Alid and 'Abbasid branches of the Hashimite family", but in Baghdad it caused the Hashimites—supported by "military chiefs of al-Harbiyya, including Muttalib and 'Isa ibn  Muhammad"—to depose  al-Ma'mun and elect Ibrahim ibn al-Mahdi Caliph.<ref name=Lapidus-1975-372-3/>

According to Shia sources, the deposing of al-Ma'um in Baghdad was not out of opposition to the wise and pious Imam Reza, but because of rumors spread by Fazl ibn Sahl. Al-Ma'mun moved Imam Reza to Merv in hopes of keeping watch over him, but was foiled by the Imam's growing popularity there. People from all over the Muslim world traveled to meet the prophet's grandson and listen to his teachings and guidance (according to these sources). In an attempt to humiliate the Imam, al-Ma'mun set him up with the greatest scholars of the world's religions, but the Imam prevailed and then informed al-Ma'mun that his grand vizier, [[Fazl ibn Sahl]], had withheld important information from him.<ref name="IRN">{{cite web |title=Why was Imam al-Reza (A.S.) Invited to Khurasan? |url=https://www.imamreza.net/old/eng/imamreza.php?id=12165 |website=Imam Reza Network |access-date=3 July 2021}}</ref>

In Baghdad, al-Maʾmūn was unseated and replaced by Ibrahim ibn Mehdi not because al-Maʾmūn's naming Imam Reza as his heir was unpopular, but because of "rumors" spread by Fazl ibn Sahl.{{citation needed|date=April 2025}}

Seeking to put down the rebellion in Baghdad, al-Ma'mun set out for the city on 12 April 818. At Tus, he stopped to visit his father's grave. However, when they reached the town of [[Sarakhs]], his vizier, Fazl ibn Sahl, was assassinated, and when they reached [[Tus, Iran|Tus]], the Imam was poisoned.  Al-Ma'mūn ordered that the Imam be buried next to the tomb of his own father, [[Harun al-Rashid]], and showed extreme sorrow in the funeral ritual and stayed for three days at the place. Nonetheless, Shia tradition states he was killed on orders of al-Ma'mun, and according to [[Wilferd Madelung]] the unexpected death of both the vizier and the successor, "whose presence would have made any reconciliation with the powerful ʿAbbasid opposition in Baghdad virtually impossible, must indeed arouse strong suspicion that Ma'mun had had a hand in the deaths."<ref name= "Madelung">{{cite web |url=http://www.iranicaonline.org/articles/ali-al-reza |title=Alī Al-Reżā, the eighth Imam of the Imāmī Shiʿites. |author=W. Madelung |date=1 August 2011 |website=Iranicaonline.org |access-date=18 June 2014 |author-link=Wilferd Madelung |archive-url=https://web.archive.org/web/20120921034922/http://www.iranicaonline.org/articles/ali-al-reza |archive-date=21 September 2012 |url-status=live }}</ref><ref name="al-Qarashi">{{cite book|title=The life of Imām 'Ali Bin Mūsā al-Ridā|last1=al-Qarashi|first1=Bāqir Sharif|others=Translated by Jāsim al-Rasheed|url=http://maaref-foundation.com/english/index.htm|access-date=22 September 2014|archive-url=https://web.archive.org/web/20110105143413/http://www.maaref-foundation.com/english/index.htm|archive-date=5 January 2011|url-status=live}}</ref>

Following the death of Imam Reza, a revolt took place in Khurasan. Al-Ma’mun tried unsuccessfully to absolve himself of the crime.<ref name="Mavani-2013">{{cite book |last1=Mavani |first1=Hamid |title=Religious Authority and Political Thought in Twelver Islam |date=2013 |publisher=Routledge |location=New York |pages=276+ |isbn=978-1135044732 |url=https://books.google.com/books?id=gJChf3qXGUkC&dq=Imam+Reza+and+al-ma-mum&pg=PA112 |access-date=3 July 2021}}</ref>