The Tahirid dynasty was an 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.

Persian, also known by its endonym Farsi or Parsi, is a Western Iranian language belonging to the Iranian branch of the Indo-Iranian subdivision of the Indo-European languages. Persian is a pluricentric language predominantly spoken and used officially within Iran, Afghanistan, and Tajikistan in three mutually intelligible standard varieties, respectively Iranian Persian, Dari Persian, and Tajiki Persian. It is also spoken natively in the Tajik variety by a significant population within Uzbekistan, as well as within other regions with a Persianate history in the cultural sphere of Greater Iran. It is written officially within Iran and Afghanistan in the Persian alphabet, a derivative of the Arabic script, and within Tajikistan in the Tajik alphabet, a derivative of the Cyrillic script.