The Banū Aws (Arabic: بنو أوس pronounced [ˈbænuː ʔæws], "Sons of Aws") or simply Aws (Arabic: أوس; also Romanized as Aus) was one of the main Arab tribes of Medina. The other was Khazraj, and the two, constituted the Ansar ("helpers [of Muhammad]") after the Hijra.
Aws and Khazraj were known as Banū Qayla (بنو قيلة [ˈbænuː ˈqɑjlæ]) in pre-Islamic era.
The word al-Aws means "the gift", probably a contraction for Aws Manāt (Arabic: أوس مناة, "the gift of Manāt"). The name was changed in Islamic times to Aws Allāh (Arabic: أوس الله).
About 300 A.D., during the emigration of Kahlān from Yemen prior to the Great Flood of Mar'ib Dam, Thaʻlaba bin ʻAmr, grand father of al-Aws, separated from his tribe and settled in Yathrib (Medina), which was then controlled by Jewish clans, and Banū Qayla were subordinate to the Jews for some time, until Mālik bin ʻAjlān of Khazraj asserts independence of the Jews, so Aws and Khazraj obtained a share of palm-trees and strongholds. Thus, about 5th century, Banū Qayla took control of Yathrib and Jews retired into the background for about a century.
During these periods before Hijra, Abū Qays al-Aslat of the clan of Wāʼil, the leader of Aws, gave away the leadership to Ḥuḍayr bin Simāk of ʻAbd al-Ashhal. After a serious defeat, ʻAbd al-Ashhal and Ẓafar were withdrawn from Yathrib. The opposing leader, ʻAmr bin Nuʻmān of the Khazrajite clan of Bayāḍa, drove the Jews tribes of Banū Qurayẓa and Banū Naḍīr into alliance of the two. Nomads of Muzayna joined them too. Most of the Khazraj as well as the Jews tribe Banū Qaynuqāʻ and the nomadic Juhayna and Ashjaʻ suppurted ‘Amr bin Nu‘mān. The Awsite clan of Ḥāritha remained neutral. Then, about 617 A.D., The Battle of Buʻāth began: Aws forced back at first, but finally defeated their opponents. The leaders of both sides were killed.