When his brother al-Wāthiq died, the oath of allegiance was given to him in Dhū al-Ḥijjah, in the year 232 AH.
He transmitted reports from his father and from Yaḥyā ibn Aktham.
He was dark-complexioned and handsome, with attractive eyes, a slender build, lightly bearded cheeks, and of medium stature. His mother’s name was Shujāʿ.
Khalīfah ibn Khayyāṭ said: “When al-Mutawakkil assumed the caliphate he openly upheld the Sunnah, spoke about it in his assemblies, and wrote to all provinces abolishing the miḥnah, expanding the sphere of the Sunnah, and supporting its adherents. In Ṣafar 244 AH al-Mutawakkil arrived in Damascus; it pleased him greatly, so he resolved to settle there, moved the state bureaus to the city, ordered construction, granted the Turkish troops a sum with which they were satisfied, and built a large palace in Darayyā adjacent to al-Mizzah.⦗1⦘”
ʿAlī ibn al-Jahm said: “Al-Mutawakkil wore his hair long, down to his earlobes, like his father and al-Maʾmūn.⦗2⦘”
Al-Fasawī reported that after two months he returned from Damascus to Sāmarrāʾ.
It was also said that Damascus had been recommended to him because it suited his temperament and would cure the ailments that afflicted him in Iraq.
Khalīfah⦗3⦘ further stated: “He led the people in the ḥajj before becoming caliph.”