Ferdowsi's Shahnameh was not conceived as a national epic, but it does encapsulate another kind of group identity: it provides context and meaning for the glorious pedigree of the Iranian aristocracy. Ferdowsi himself was a member of the Khorasani dehqān gentry whose collective effort in the tenth century CE was turned towards preserving and reshaping their own history and literary heritage in the terms of the new era. This article analyzes the final section of the Shahnameh, dealing with the reign and death of the last Sasanian king, Yazdegerd III. As such, this section provides crucial clues for the function of the Shahnameh as a means to construct meaning for Ferdowsi's own group in his own time. The description of this crucial moment in history, pivoting between the era of Iranian kingship and the Islamic era, suggested possible modes for interpreting the present. The study reads this section of the Shahnameh with close attention to the use of the word nezhād (“lineage”), which circumscribes the identity of both the aristocrats of Ferdowsi's present, and the kings and heroes of the mythic past. In doing so, the transition between eras appears as a tragedy of nezhād, as the Sasanian dynasty is extinguished, raising permanent existential ambiguities for the entire class of Iranian gentry whose genealogies were associated with it.