Sa'id ibn Qays belonged to the Sabi' branch[1] of the South Arabian Hamdan tribe and was a purported descendant of a Himyarite king.
[3] Sa'id fought in the early Muslim conquests and became one of the leading tribal nobles of Kufa, one of the two main Arab garrison towns of Iraq.
In this capacity, he led his men in the battles of the Camel (656) near Basra and Siffin (657) on the frontier of Syria, as well as another campaign under Ali in 661.
He is mentioned as one of the chiefs of the Yaman (South Arabians) during the reigns of the Umayyad caliphs Mu'awiya I (r. 661–680) and Yazid I (r. 680–683).
[2] Sa'id was the maternal grandfather of the Kufan tribal noble, prominent commander and rebel leader Ibn al-Ash'ath.