811–825) was the leader of a rebellion of the Qays tribe in the Jazira against the central Abbasid government during the civil war of the Fourth Fitna.
Nasr appears in 811/812, when Caliph al-Amin (r. 809–813) sent his general, Abd al-Malik ibn Salih, to Syria to recruit troops for the civil war against his brother, al-Ma'mun (r. 813–833).
Despite his ability, Tahir failed to make any progress against Nasr and the Arab tribesmen, who continued to raid and terrorize the region for a further decade.
[3][9] Over the next five years, Abdallah gradually reduced Nasr's territory and killed off his followers, until he was driven to his last refuge, the fortress of Kaysum.
In the end, in 824 or 825, Nasr was forced to offer his surrender in exchange for a document guaranteeing his safety—preserved by al-Tabari along with a letter sent to him exhorting him to lay down arms—a request which was granted by al-Ma'mun.