Tuhia he haere tonu mo tenei waahanga - Ṭāhir ibn Ḥusayn (, "Tâhereben Hoseyn";, "Tahir bin al-Husayn"), e mohiotia ana ko Dhul-Yamīnayn (, "te ambidextrous"), me al-Aʿwar (, "te kanohi kotahi"), he rangatira Iranian me te kawana i te wa o te caliphate Abbasid. Ko te mea nui, i mahi ia i raro i te al-Ma'mun i te wā o te Fourth Fitna
ā, i ārahi i ngā hōia i hinga ai i a al-Amin, i meinga ai a al-Ma'mun hei "caliph". I whakawhiwhia ia hei kawana o Khorasan, i tohu i te timatanga o te whare rangatira o Tahirid.