Everything, in fact, points to the correctness of one of the views entertained by Herodotus, that this expedition was aimed against Athens and Eretria alone.
It was in a sense the completion of the work done in the suppression of the revolt, and a precaution against the recurrence of such an outbreak. Not merely must the European Greeks be taught the danger of interfering in the affairs of the empire, but the subjugation of the interfering states must show the Ionians that in future they could not expect help from their free kinsmen beyond the seas.
It is, however, impossible to suppose that the Persian design ended here, and that, had a footing been once won in Attica, the Persian Government would have contented itself with the punishment of that state, and then have withdrawn its troops. H. vi. 96. The action with regard to Naxos and the other Islands on the passage of the Ægean shows that Persia intended to acquire this most effective line of communication; in other words, that the second motive of this expedition was identical with that which had made Artaphernes the satrap so keen to take up the design of Aristagoras in 500 B.C., the desire to acquire a base in the Western Ægean against European Greece. The expedition was to be the preliminary step in larger schemes of conquest.
It was in accord with Persian practice at this time that the command of the new venture should be entrusted to some other general than the leader in 492. H. vi. 94. Mardonios was deposed, says Herodotus, because he had mismanaged the previous expedition. That, as has been seen, had not been the case; and the change of leadership seems to have been simply an instance of the regular policy of Darius with regard to high military command.
The new generals were Datis, a Mede, and Artaphernes, the son of the great satrap of the same name, and nephew of Darius.
From Susa the army was conducted to the Aleian plain in Cilicia, where the fleet and transports met it. On these vessels it was embarked and sailed to Ionia.
Herodotus never mentions the number of the force. It is a somewhat strange omission on his part, the more so as it is his habit to give some estimate of the strength of the Persian armies on important expeditions. It is probable that, defective as is his appreciation of numbers, he could not accept the exaggerated estimates of later tradition. H. vi. 95. He says that the number of triremes was 600.[60] Whether this be correct or not, it is probable that if it errs, it errs on the side of exaggeration. But assuming it to be correct, the numbers of the expedition were extraordinarily small for a Persian enterprise. Special transports were, indeed, provided for the horses; but the men of the land army were embarked on board the fleet.[61] When the smallness of the ships of those days, the largeness of the crews necessary to work the oarage, and the fact that in the present instance a considerable amount of room was taken up by the horses, are taken into consideration, it is impossible to suppose that the average number of men on board each vessel effective for service on land can have amounted to more than a hundred; it is probable that it amounted to considerably less.
The available force in that case was 60,000 at most, and may not have been more than 40,000.[62]
PERSIANS AT NAXOS AND DELOS.
From Samos the fleet sailed past Ikarios, and through the Islands. It first touched at Naxos, and attacked it. There the success was partial. The town and its temples were burnt; but the mass of the population escaped to the hills.