Humayd was the son of Qahtaba ibn Shabib al-Ta'i, who along with Abu Muslim led the Abbasid Revolution that toppled the Umayyad Caliphate.
Along with his brother Hasan, Humayd was active in the Abbasid cause in Khurasan during the years before the Revolution, serving as a deputy naqib.
[1] After the Revolution, Humayd attached himself to the governor of Syria, Abdallah ibn Ali, and even joined him when he rebelled against the Caliph al-Mansur (r. 754–775) in 754.
[1][2] In 762/63 he served under Isa ibn Musa in the suppression of the rebellion of Muhammad al-Nafs al-Zakiyya.
[1][2] He was briefly succeeded by his son, Abdallah, who later played a prominent role in the civil war of the Fourth Fitna.