had deposited their Eretrian prisoners, whom they had reserved to be led away captives into Upper Asia, there to hear their doom from the lips of King Darius himself. Moreover, the men of Athens knew that in the camp before them was their own banished tyrant, Hippias, who was seeking to be reinstated by foreign scimitars in despotic sway over any remnant of his countrymen that might survive the sack of their town, and might be left behind as too worthless for leading away into Median bondage. The numerical disparity between the force which the Athenian commanders had under them, and that which they were called on to encounter, was fearfully apparent to some of the council. The historians who wrote nearest to the time of the battle do not pretend to give any detailed statements of the numbers engaged, but there are sufficient data for our making a general estimate. Every free Greek was trained to military duty: and, from the incessant border wars between the different states, few Greeks reached the age of manhood without having seen some service. But the muster-roll of free Athenian citizens of an age fit for military duty never exceeded thirty thousand, and at this epoch probably did not amount to two-thirds of that number. Moreover, the poorer portion of these were unprovided with the equipments, and untrained to the operations of the regular infantry. Some detachments of the best armed troops would be required to garrison the city itself, and man the various fortified posts in the territory; so that it is impossible to reckon the fully equipped force that marched from Athens to Marathon, when the news of the Persian landing arrived, at higher than ten thousand men. [The historians who lived long after the time of the battle, such as Justin, Plutarch and others, give ten thousand as the number of the Athenian army. Not much reliance could be placed on their authority, if unsupported by other evidence; but a calculation made from the number of the Athenian free population remarkably confirms it. For the data of this, see Boeck's "Public Economy of Athens," vol. i. p. 45. Some METOIKOI probably served as Hoplites at Marathon, but the number of resident aliens at Athens cannot have been large at this period.] With one exception, the other Greeks held back from aiding them. Sparta had promised assistance; but the Persians had landed on the sixth day of the moon, and a religious scruple delayed the march of Spartan troops till the moon should have reached its full. From one quarter only, and that a most unexpected one, did Athens receive aid at the moment of her great peril.