The two principal Himyarite families that established themselves in Homs were the Dhu Asbah and Dhu'l-Kala. The latter had been the most influential family in South Arabia before the advent of Islam there. Among the leaders of the conquering Muslim troops was the Himyarite prince Samayfa ibn Nakur of the Dhu'l-Kala. The Asbah chief Kurayb ibn Abraha Abu Rishdin led the Himyar of Homs, but he later moved to Egypt with most of the Dhu Asbah. Members of that family, Abraha ibn Sabbah and his son Abu Shamir, had participated in the Muslim conquest of Egypt in 640–641. Samayfa was another dominant figure of the city and was referred to in the early Muslim sources as the "king of Himyar". During the governorship of Syria by Mu'awiya ibn Abi Sufyan (640s–661), the Himyarites supported him against Caliph Ali () during the First Muslim Civil War. At the Battle of Siffin with Ali in 657, Samayfa led the Homs contingent in Mu'awiya's army and was slain. He was succeeded by his son Shurahbil as the power-broker of the Homs tribesmen. According to the historian Werner Caskel, the Himyar and the other South Arabian tribes of Homs, including the Hamdan, formed a confederation called after their supposed ancestor Qahtan in opposition to the Quda'a confederation, whose constituent tribes had long resided in Syria before the advent of Islam. To the chagrin of the South Arabians in Homs and the Qays tribes of northern Syria, the Quda'a, led by the Banu Kalb tribe, held the supreme position among the tribal groups in the courts of the first Umayyad caliphs Mu'awiya ibn Abi Sufyan () and Yazid I (). With the strong presence of the Himyarite elite and South Arabian tribesmen in Homs, their scholars there developed and propagated an ideology of Qahtanite preeminence that sought to compete with the elite groups of Islam, including the Quraysh, whose members held the office of the caliph. To that end, they composed and transmitted narratives of the pre-Islamic South Arabian kingdoms, including war stories of these kings' far-flung conquests and heroics and tales of their wealth. After the deaths of Yazid I and his son and successor Mu'awiya II in 683 and 684, respectively, the Qahtan and the Qays backed the rival caliphate of Abd Allah ibn al-Zubayr, who was based in Mecca, while the Quda'a supported the candidacy of the Umayyad Marwan I. Kurayb ibn