 The backbone of the Sasanian feudal army, they were largely autonomous.The Sasanian shahs had little control of the "wuzurgan", and attempts to restrict them were usually costly to the shah (as indicated by the fate of the three previous shahs).The Parthian nobility worked for the Sasanian shah for personal benefits, out of loyalty, and (possibly) an awareness of the Aryan (Iranian) kinship they shared with their Persian overlords.