He was a son of Hasan ibn Ali and Khawla bint Manzur.
He was a grandson of the fourth caliph Ali (r. 656–661) and a great-grandson of the Islamic prophet Muhammad.
His father Hasan ibn Ali ruled briefly as caliph in 661 and was a grandson of the Islamic prophet Muhammad.
Ahmad ibn Ibrahim Hasani, in a tradition quoted from Abu Mikhnaf, he said that his age at that time was nineteen or twenty.
Also, Hasan al-Muthanna had sons named Abd Allah al-Mahd, Ibrahim al-Ghamr and Hasan al-Muthallath from Fatima bint Husayn; Ja'far and Da'wud from Umm al-Walad; Muhammad from Ramla bint Sa'id ibn Zayd; who continued a third generation of Imam Hasan.