The Banu al-Qayn, along with other Quda'a tribes, such as the Banu Kalb, backed Marwan I in the latter's bid to become caliph during the Second Muslim Civil War.[1] During a territorial dispute between the Banu al-Qayn and Banu Kalb over Wadi Sirhan, Marwan's son and successor, Abd al-Malik, ruled in favor of the Kalb.[1] About six hundred al-Qayni tribesmen took part in the Umayyad campaign against the Kharijite rebel Bahlul in 737.[1] According to historian W. Montgomery Watt, "the last that is heard" of the Banu al-Qayn was in 792, during the Abbasid era, when they were involved in intertribal fighting in Damascus.[1]