This thesis is concerned with the Middle Persian epic of K arnamag i Ardaxš ir i Pabag an, an epic biography of the founder of the Sasanian dynasty. The basic proposition of the thesis is that the text, composed many centuries after the lifetime of its subject, is a reflection of the ideals of its time of composition (sixth-seventh century CE). By using internal evidence from the text, as well as contemporary and later evidence for the kingship of Ardaxšir, the present work tries to find possible reasons behind the historical revisions evident in the text. It is suggested, based on linguistic and stylistic reasons that the text was composed approximately 300 years after the time of Ardaxšir I himself (224-240 CE). Further discussions on the depiction of the royal genealogy of Ardaxšir and his successors conclude that the forging of a new lineage for the founder of the dynasty served to strengthen the claims of sixth century kings to legitimate rule. Other internal evidence, including discussions of courtly culture and mythological themes are used to suggest that Ardaxšir was indeed employed to reflect the image of an ideal king to the later monarchs of the dynasty.