Crown princes in pre Islamic Iran

The position of a crown prince in pre-Islamic Iran was affirmed in the Median and early Achaemenid eras, when sovereignty was becoming standardized, due to the influence of Mesopotamian, Urartian, and Elamite practices.

It was during this period that the Avestan word vīsō puθra ("son of the clan") was adopted to denote “crown prince.” The word later evolved into pus ī vāspuhr in Middle Persian.

By the early Achaemenid period, a king preparing to participate in a military expedition, was required to appoint his heir, in case the king would die. Usually the appointment of an heir was based on his ancestry, physical quality, and leadership features.