The Buyid dynasty, also spelled Buwayhid, was a Zaydi and, later, Twelver Shia dynasty of Daylamite origin, which mainly ruled over central and southern Iran and Iraq from 934 to 1062. Coupled with the rise of other Iranian dynasties in the region, the approximate century of Buyid rule represents the period in Iranian history sometimes called the "Iranian Intermezzo".

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.