The valor of their troops in the great combats of Platsea and Thermopylae extorted the admiration of their enemies, who have left on record their belief that, "in boldness and warlike spirit, the Persians were not a whit behind the Greeks," and that their defeat was "wholly owing to the inferiority of their equipment and training." Without proper shields, with little defensive armor, wielding only short swords and lances that were scarcely more than javelins, they dashed themselves upon the serried ranks of the Spartans, seizing the huge spear-shafts of these latter with their hands, striving to break them, and to force a way in.

No conduct could have been braver than this, which the modern historian well compares with brilliant actions of the Romans and the Swiss.

The Persians thoroughly deserved to be termed (as they are termed by AEschylus), a "valiant-minded people;" they had boldness, elan, dash, and considerable tenacity and stubbornness; no nation of Asia or Africa was able to stand against them; if they found their masters in the Greeks, it was owing, as the Greeks themselves tell us, to the superiority of Hellenic arms, equipment, and, above all, of Hellenic discipline, which together rendered the most desperate valor unavailing, when it lacked the support of scientific organization and united simultaneous movement.
The energy of the Persians during the earlier years of their ascendancy is no less remarkable than their courage.

AEschylus speaks of a mysterious fate which forced them to engage continually in a long series of wars, to take delight in combats of horse, and in the siege and overthrow of cities.

Herodotus, in a tone that is not very different, makes Xerxes, soon after his accession, represent himself as bound by the examples of his forefathers to engage his country in some great enterprise, and not suffer the military spirit of his people to decay through want of employment.