Al-Muʿtaṣim was fair-skinned, his beard long and reddish-blond(1); he was of medium build and had a ruddy complexion.

His mother was an umm walad (a slave-concubine who had borne a child) named Māridah. He was one of six sons of Hārūn al-Rashīd, each of whom was called Muḥammad: Abū Isḥāq al-Muʿtaṣim, Abū al-ʿAbbās al-Amīn, Abū ʿĪsā, Abū Aḥmad, Abū Yaʿqūb, and Abū Ayyūb—so reported Hishām ibn al-Kalbī(2).

After him, the caliphate passed to his son Hārūn al-Wāthiq.

Ibn Jarīr relates that his vizier Muḥammad ibn ʿAbd al-Malik ibn al-Zayyāt composed this elegy for him(3):

I spoke when they buried you, when the hands(4)
of earth and clay were hurled upon your bier:
“Depart; how excellent a guardian you were for worldly affairs,
and how excellent a champion you were for the faith.
May Allah not mend a nation that has lost one like you
save by granting it another like Hārūn.”

Marwān ibn Abī al-Janūb—the nephew of Marwān ibn Abī Ḥafṣah—recited(5):

Abū Isḥāq died at mid-morning, and with him we died;
by evening, through Hārūn, we came back to life.
If Thursday brought us what we despised,
it also brought us what we desired.

The Caliphate of Hārūn al-Wāthiq bi-Allah ibn al-Muʿtaṣim

He was given the pledge of allegiance for the caliphate before his father al-Muʿtaṣim died, on Wednesday, the 8th of Rabīʿ al-Awwal of this year, 227 AH. His kunyah was Abū Jaʿfar. His mother was a Roman umm walad named Qarāṭīs. That same year she set out for the pilgrimage, but died at al-Ḥīrah and was buried in Kūfah, in the house of Dāwūd ibn ʿĪsā, on the 4th of Dhū al-Qaʿdah of this year(6).

The one who supervised the pilgrimage for the people that year was Jaʿfar ibn al-Muʿtaṣim(7).