Persian soldiers in a relief of Persepolis. Source: https://ifpnews.com/persian-architecture-in-photos-reliefs-of-persepolis/
In 546 BCE, when the Persians were laying siege to the Greek cities of Ionia following the defeat of Croesus, king of Lydia, the Spartans sent a single ship with a message for Cyrus the Great, the founder of the Persian empire (1.152-3). Cyrus was warned by a Spartan envoy not to harm any city of Greece, for the Spartans would not permit it. In reaction to this piece of effrontery, Cyrus asked other Greeks who were present: 'Who among men are the Lacedaemonians, and how many of them are there that they give such orders?' The modern reader of the text of Herodotus will have no trouble recognising the Spartans (here called Lacedaemonians), and might well know that there were not many of them, and that only 300 of them faced the Persians at the battle of Thermopylae in 480 BCE. But he or she is far less likely to know much about the Persians, other than that there were a whole lot of them and that they failed to conquer Greece and were themselves, at a much later date (334-331 BCE), conquered by Alexander the Great.
It may come as a surprise then that the Histories of Herodotus is as much about Persia as about Greece, and that individual Persians are given just as much narrative space as individual Greeks. In fact the Persian kings Cyrus, Cambyses, Darius, and Xerxes, as well as Xerxes' cousin Mardonius, figure even more largely in the narrative than the Athenian general Themistocles or the Spartan king Leonidas. On a larger scale, the whole structure of the Histories is built upon the birth, growth, and checking of the Persian empire. The Persians are the driving force of the history, and the advance of the narrative is inextricably linked to their efforts to expand their empire. It can hardly be a coincidence that both the first (1.1-4) and the last (9.122) narratives in this massive work are focalised through the eyes of the Persians.”
Summary of the study of Michael Flower Herodotus and Persia, contribution to The Cambridge Companion to Herodotus, edited by Carolyn Dewald and John Marincola, Cambridge University Press, 2006
Source: https://www.cambridge.org/core/books/abs/cambridge-companion-to-herodotus/herodotus-and-persia/BFFD6A8DD9E5816C6255B634E92056F7
Michael Flower, Chair, Department of Classics David Magie ’97 Class of 1897 Professor of Classics, Princeton University.