Who is Rostam's ancestor? Identification of the ancestor of the Sam dynasty based on historical-comparative linguistics

One of the vague words of Shāh-nāma is the word "Karimān", which is mentioned in Shāh-nāma as Rostam's ancestor. Contemporary scholars, influenced by Mo'in, considered the meaning of "Karimān" is the plural of the word "Karim", and lexicographers, epic poets, and linguists called it a special name, but they could not express the etymology of the word.Using Diachronic Etymology and Comparative Linguistics, this paper examines the historical forms of the word (Kār-framān, Kahrumān and Qahramân) in comparison with similar cases in official sources and folklore literature in Persian, Turkish, Kurdish and Arabic. The old form of the word, " Kār-framân", in the official usage meant agent in the court in matters such as treasury and in military usage, meant the king's appointment in of the military department. For this reason, this title has been attributed to Sistani heroes, and in particular, to Rostam's ancestor. The implicit meaning of courage is also derived from the military usage of the word, used in the Arabicized form of the word ("Qahramân"). Ferdowsi also mentioned the form of the special name of this word as the name of Rostam ancestor, and changed "Kahrumān" to "Karimān" in order to rhyme with Narimān. The reconstruction of the story of this character in the cycle of Sistani epics, clarified his relationship with "Hüšang-Shāh", who in Sistani sources was the third king of Iran. Therefore, the problem of Karimān's attribution to Hüšang was also solved and it became clear why he was named the third king of Iran.