Did the Achaemenids have throne names?
When Ochus, the son of Artaxerxes I, ascended the throne in 424/423 BCE after defeating his brother, he adopted the name "Darius" (𐎭𐎠𐎼𐎹𐎺𐎢𐏁, Dārayavaʰuš). This provides the earliest evidence that Achaemenid kings assumed throne names, which might differ from their original names. These throne names served strong legitimizing purposes: Ochus, whose reign was contested, sought to convey his strength and right to rule by adopting the name of one of his most illustrious predecessors.
But were throne names assigned when a prince was designated as heir to the empire, as was the case in the Neo-Assyrian Empire? This remains uncertain. Additionally, did the practice of using throne names predate Darius II? This is possible, as several Greek sources—Herodotus and Strabo in particular—suggest that even the great Cyrus was not born with the name by which he is known.
Interestingly, some scholars argue that the name Cyrus (𐎤𐎢𐎽𐎢𐏁, Kūruš) is not of Indo-Iranian origin. Some suggest it might derive from Elamite, while Strabo (15.3.6) claims the name comes from a river flowing through Persis near Pasargadae. If Cyrus’s name was indeed non-Iranian, it could support the theory that "Cyrus" was a throne name, as it would make more sense if he were born with a distinct Iranian name. However, this remains a matter of debate.
