farn-sasan and sasanian ardashir i share a similar name. because of this and the fact that both of their coin has a fire altar, historians think sasanians and indo-parthians may have had common ancestry. historians say that farn-sasan and sasanian ardashir i were rivals. both wanted to be the king of kings. the iranologist khodadad rezakhani argues that farn-sasan was a superior of ardashir i. he said that ardashir i was only able to say that he was the king of kings after he defeated farn-sasan in 226 and ended indo-parthian rule.