Then the year 201 AH began.
During it: the people of Baghdad pressed Manṣūr ibn al-Mahdī to assume the caliphate, but he refused. They next urged him to act as al-Maʾmūn’s deputy and to have the Friday sermon delivered in his name; he agreed. This took place after the Baghdadis had expelled ʿAlī ibn Hishām, the representative of al-Ḥasan ibn Sahl, from their midst, and many battles ensued because of it.
That same year tribulation spread at the hands of the ʿayyārūn (urban brigands), the shuṭṭār (bandits), and other profligates in Baghdad and its surrounding villages. They would approach a man, asking him for money as a loan or gift; if he refused, they stripped his house of everything, and might even molest his boys and womenfolk. They would descend upon a village, drive off its cattle and livestock, and seize whatever boys or women they wished. They plundered the inhabitants of Quṭrubbul (1), leaving them with absolutely nothing.
A man called Khālid al-Darīyūsh and another named Sahl ibn Salama, Abū Ḥātim al-Anṣārī of Khurasan, volunteered to oppose them, and a band of commoners gathered around the two men (2). They repelled the brigands’ evil, fought them, gained the upper hand, and prevented them from spreading corruption in the land. Affairs returned to normal in Shaʿbān and Ramaḍān, and to Allah belong all praise and grace (3).
In this same year, in Shawwāl, al-Ḥasan ibn Sahl returned to Baghdad, reconciled with the troops, and Manṣūr ibn al-Mahdī together with the commanders who had joined him withdrew.
Also that year al-Maʾmūn pledged allegiance to ʿAlī al-Riḍā ibn Mūsā al-Kāẓim ibn Jaʿfar al-Ṣādiq ibn Muḥammad al-Bāqir ibn ʿAlī Zayn al-ʿĀbidīn ibn al-Ḥusayn the Martyr, son of ʿAlī ibn Abī Ṭālib, appointing him heir apparent after him. He named him “al-Riḍā from the Family of Muḥammad, ﷺ,” abandoned the wearing of black, donned green, obliged his troops to do likewise, and wrote of this to all provinces and regions. The pledge was taken on Tuesday, the second night of Ramaḍān in the year 201 AH. Al-Maʾmūn did so because he regarded ʿAlī al-Riḍā as the most excellent member of the Prophet’s household, and saw that none of the Abbasids equalled him in knowledge (4) or piety; therefore, he appointed him his successor.