The Tahirid dynasty (, ) was a Sunni Persian "dehqan" dynasty, that effectively ruled 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. The Tahirids initially made their capital in Merv but was later moved to Nishapur. The Tahirids, however, were not an independent dynasty—according to Hugh Kennedy: ""The Tahirids are sometimes considered as the first independent Iranian dynasty, but such a view is misleading. The arrangement was effectively a partnership between the Abbasids and the Tahirids." Indeed, the Tahirids were loyal to the Abbasid caliphs and in return enjoyed considerable autonomy; they were in effect viceroys representing Abbasid rule in Persia. The tax revenue from Khorasan sent to the caliphal treasury in Baghdad was perhaps larger than those collected previously.