The Modification of the Parthian History in the National-Epic Narrative and its Causes

Parthian history has come with high briefly, in Iranian national epic narrative that is mentioned in Islamic sources, in spite of that dynasty has the longest period in history of Iran. As in most cases, except the names of kings and refers to the number their king’s years, hasn’t something else about them. This brevity to the extent that reduced to less than half the real time, Length of time of their government. up to now, this case Has occupied many researchers And has been expressed many opinions on the cause of this brevity.The common trait of all of them,this is that attributed this case to the Sassanid deliberate policy, But, as yet, has not done much to ponder on the reason for adopting this policy by the Sassanids. This article seeks to review how and why this question with Using historical research and through data available. This paper shows that Unlike the famous, This distortion has Don, Not due to religious beliefs and not by priests, But by The Sasanian court nobility,To solve political - social problems of Sasanian court and Iranian nobility,that were caught them, at the same time.