The investiture relief of Ardashir I at Naqsh-e Rustam, carved around 230 CE, is one of the foundational monuments of early Sasanian ideological art. The scene depicts Ardashir receiving the ring of sovereignty (diyadem, cydaris, or xvarrah-connoting diadem) from Ohrmazd, establishing visually and textually the divine mandate of the new dynasty. Beneath the horses of king and god is an inscription, partly in Middle Persian and partly in Parthian, identifying the figures and articulating Ardashir’s legitimising titles. The fragment you provided is the portion beside or beneath Ardashir’s horse, where both languages name him mazdēsn bay Ardašīr šāhān šāh ērān, “the divine, Mazda-worshipping Ardashir, king of kings of the Iranians,” followed by a genealogy anchoring him in the lineage of Sāsān. The multilingual format echoes Achaemenid practice while responding to the linguistic landscape of early third-century Iran, where Middle Persian was the emerging court language but Parthian remained widely understood among elites. The inscription thus articulates a new political order without severing ties to earlier imperial traditions.

The iconography operates in tandem with the inscription to construct Ardashir’s authority. Both king and god trample defeated enemies: beneath Ardashir lies the last Arsacid king, Artabanus IV, while beneath the horse of Ohrmazd is the prone figure of Ahriman. This pairing creates a theological analogy—Ardashir’s victory over the Arsacid rivals mirrors Ohrmazd’s cosmic triumph over evil—embedding the political revolution within a Zoroastrian cosmological frame. The imagery also reflects Achaemenid precedents at nearby Naqsh-e Rustam, where Darius I’s Behistun narrative and the tomb reliefs proclaim divine legitimation and triumphant kingship. Yet the Sasanian sculptors adapt these models, shifting from the Achaemenid emphasis on the king before Ahuramazda’s symbol to a more intimate, tactile act of investiture in which the god physically hands the royal ring to the king. This visual idiom draws partly on Hellenistic royal iconography—particularly the exchange of wreaths or fillets seen in Seleucid and Parthian coins—but reworks it into a distinctly Iranian theological and political statement.

The inscription’s emphasis on Ardashir as mazdēsn (“Mazda-worshipping”) has attracted extensive scholarly debate. While scholars such as Daryaee have argued that this is the first explicit adoption of the title by an Iranian king, earlier Achaemenid evidence complicates this reading. Darius I repeatedly proclaims in the Behistun inscription that he worships Ahuramazda and acts through the god’s favour, and he urges others to worship Ahuramazda. Ardashir’s innovation, therefore, may lie less in the theology than in the formalisation of a title integrating religious devotion directly into royal titulature. The term bay (“divine” or “lordly”) compounds this claim to elevated status but does not, despite certain Hellenistic resonances, imply literal apotheosis; the Sasanians, like the Achaemenids before them, refrained from claiming divinity in the manner of Greco-Roman rulers. Instead, the title situates the king within a cosmological hierarchy while maintaining a clear distinction between human and divine realms.

The formula šāhān šāh ērān (“king of kings of the Iranians”) is equally significant. Earlier Arsacid rulers had used “king of kings,” but Ardashir’s phrase introduces ērān, marking one of the earliest political deployments of the ethnic–geographical term that would evolve into “Iran.” This linguistic shift participates in a broader Sasanian effort to redefine imperial identity around Zoroastrian Iranian heritage. By grounding his authority in the land and people of ērān, Ardashir contrasts his rule with the more diverse and less centralised Arsacid polity, asserting a restored and ideologically unified Iranian empire. The genealogy that follows, identifying him as “son of the papak” (pābag) and descendant of Sāsān, further strengthens this ideological restructuring. Sāsān is elevated into a dynastic founder, and the newly created narrative of Sasanian origins acquires monumental, stone-carved legitimacy.

The relief’s location at Naqsh-e Rustam also plays a crucial role in its ideological work. The site, already sanctified by the rock-cut tombs of Achaemenid kings, provided an arena in which Ardashir could visually inscribe himself into the lineage of the ancient empire. This deliberate spatial appropriation signals historical continuity while proclaiming restoration – an argument that the Sasanians were rightful heirs to the Achaemenids, reviving the xvarrah (royal glory) that had lapsed under the Arsacids. The animal protomes and the monumental scale further imbue the relief with a sense of cosmic authority, evoking both royal hunt motifs and the long-standing Iranian association between kingship, animal symbolism, and divine favour.

Viewed together, the inscription and relief constitute a political manifesto in stone: Ardashir declares his kingship divinely conferred, historically grounded, cosmologically aligned, and ethnically defined. The integration of textual and visual elements presents a powerful ideological synthesis: Ohrmazd’s gesture of investiture legitimises Ardashir’s victory; Ardashir’s trampling of the Arsacid king mirrors the god’s triumph over evil; the multilingual inscription situates the dynasty within both Iranian and broader imperial traditions; and the choice of site overlays the new monarchy onto the memory of the Achaemenids. The result is one of the clearest expressions of early Sasanian state ideology, articulating a new form of Iranian kingship that blends inherited traditions with novel formulations of religious and political authority.