Then the year 196 AH began.
In that year Abū Muʿāwiyah al-Ḍarīr, Muḥammad ibn Khāzim—one of the trustworthy, eminent, and well-known masters of hadith—passed away, as did al-Walīd ibn Muslim al-Dimashqī, a disciple of al-Awzāʿī.
That same year Muḥammad al-Amīn imprisoned Asad ibn Yazīd because Asad had reproached the caliph for his frivolity, his neglect of the subjects’ welfare, and his indulgence in hunting and other pastimes at so critical a time.
Al-Amīn also dispatched his uncle Aḥmad ibn Mazīd together with ʿAbd Allāh ibn Ḥumayd ibn Qaḥṭabah at the head of forty thousand men—twenty thousand under each commander—to Hulwān to fight Ṭāhir ibn al-Ḥusayn, the field commander representing al-Maʾmūn. When they approached Hulwān, Ṭāhir dug a trench around his army and set about sowing discord between the two commanders; they quarreled, withdrew, and never engaged him. Ṭāhir then entered Hulwān. A letter from al-Maʾmūn reached him instructing him to hand over everything under his control to Harthama ibn Aʿyan and proceed to al-Ahwāz, and he complied.
During this year al-Maʾmūn elevated his vizier al-Faḍl ibn Sahl, entrusted him with far-reaching powers, and conferred upon him the title Dhū’l-Riyāsatayn (Holder of the Two High Offices, civil and military).
In the same year al-Amīn appointed ʿAbd al-Malik ibn Ṣāliḥ ibn ʿAlī as his governor over Syria—having released him from Hārūn’s prison—and ordered him to send troops to fight Ṭāhir and Harthama. When ʿAbd al-Malik reached al-Raqqah he remained there, writing to the Syrian notables to win their allegiance and summon them to obedience; a great many answered his call. Fighting then broke out, beginning with the people of Ḥimṣ; matters escalated, the struggle dragged on, and ʿAbd al-Malik ibn Ṣāliḥ died there. The army returned to Baghdad accompanied by al-Ḥusayn ibn ʿAlī ibn Māhān. The people of Baghdad received him with honor in the month of Rajab of that year. Once he had entered the city, a messenger from al-Amīn came looking for him.
He said, “By Allah, I am neither his boon-companion nor his jester; I hold no office for him, and none of his money has ever passed through my hands (1). Why, then, is he summoning me on this night?”
Reason for the deposition of al-Amīn, son of Zubaydah, and how the caliphate passed to his brother al-Maʾmūn
When morning came, al-Ḥusayn ibn ʿAlī ibn Māhān—who had not gone to al-Amīn despite the caliph’s summons after his return with the Syrian army—addressed the people. He incited them against al-Amīn, spoke of his frivolity, his devotion to amusement, and other acts of disobedience, and declared that one in such a condition was unfit for the caliphate and sought only to set the people at enmity with one another. He urged them to rise up against the caliph and march upon him. A vast multitude rallied to his side. Muḥammad al-Amīn sent cavalry against them, and they fought for a good part of the day. Al-Ḥusayn then ordered his men to dismount and fight on foot with swords and spears, whereupon the opposing force broke and fled.