The Tahirid dynasty was a culturally Arabized, Sunni Muslim dynasty of Persian dehqan origin that ruled as governors of Khorasan from 821 to 873 as well as serving as military and security commanders in Abbasid Baghdad until 891. The dynasty was founded by Tahir ibn Husayn, a leading general in the service of the Abbasid caliph al-Ma'mun. For his support of al-Ma'mun in the Fourth Fitna, he was granted the governance of Khorasan.