Fadl ibn Rabi'ah was the progenitor of the Al Fadl clan,[21] while Mira and Faraj became the ancestors of the Al Mira and Al Faraj clans, respectively.[2][22] Collectively, these clans formed the Banu Rabi'a, and together with their allies, they dominated the desert and steppe regions between the Euphrates valley in the north to the central Najd and northern Hejaz in the south.[23] During Ayyubid rule in Syria (1182–1260), the emirs of Al Fadl and Al Faraj alternated as umara al-'ʿarab ("commanders of the Bedouin tribes"; sing. amir al-ʿarab).