Abstract: Characterology of individuals in Sassanian memorial artwork involves benefts from the simultaneous use of detailed historical information and archaeological evidence. In the present paper, the identity of the Iranian nobleman, who seems to be leading the captive Roman Caesar towards the King, Ardashir in the rock relief of Darabgerd, has been challenged. For this reason, investigating the governmental structure of the Sassanid dynasty, the hierarchy of the ranks, the temporary confusion about the existence and function of some positions, as well as the equivalent terms representing them are unavoidable. The historical content of Darabgerd rock relief, displaying Ardashir I’s victory over the Romans, has shifted the authors’ mentality in identifying the mentioned fgure onto a military high rank. Therefore, differing with Hinz (2006:206-207), who has attributed this fgure to “Bidaxš of Shapur”, a character whom he believes to be the commander of the armed forces, the authors insist on attributing this fgure to “Pāpak Hazārpat” as the commander of the royal guard. A historical approach, conducted as a comparative study of the historical narratives associated with the functional domain of the ranks of “Bidaxš”, “Hazārpat”, “Sepahbad” and “Asbbad” with the positions of the above-mentioned ranks in inscriptional evidence of Shapur I in the Ka'ba-ye Zartosht (meaning the Cube of Zoroaster) and Nerseh at Pāikuli and also the comparative picturology among some Sassanian memorial artwork, has attempted to explicate this ascription.