The inaction of the Asiatic commanders, during this interval, appears strange at first sight; but Hippias was with them, and they and he were aware of their chance of a bloodless conquest through the machinations of his partisans among the Athenians. The nature of the ground also explains, in many points, the tactics of the opposite generals before the battle, as well as the operations of the troops during the engagement. The plain of Marathon, which is about twenty-two miles distant from Athens, lies along the bay of the same name on the north-eastern coast of Attica. The plain is nearly in the form of a crescent, and about six miles in length. It is about two miles broad in the centre, where the space between the mountains and the sea is greatest, but it narrows towards either extremity, the mountains coming close down to the water at the horns of the bay. There is a valley trending inwards from the middle of the plain, and a ravine comes down to it to the southward. Elsewhere it, is closely girt round on the land side by rugged limestone mountains, which are thickly studded with pines, olive-trees, and cedars, and overgrown with the myrtle, arbutus, and the other low odoriferous shrubs that everywhere perfume the Attic air. The level of the ground is now varied by the mound raised over those who fell in the battle, but it was an unbroken plain when the Persians encamped on it. There are marshes at each end, which are dry in spring and summer, and then offer no obstruction to the horseman, but are commonly flooded with rain, and so rendered impracticable for cavalry, in the autumn, the time of year at which the action took place. The Greeks, lying encamped on the mountains, could watch every movement of the Persians on the plain below, while they were enabled completely to mask their own. Miltiades also had, from his position, the power of giving battle whenever he pleased, or of delaying it at his discretion, unless Datis were to attempt the perilous operation of storming the heights. If we turn to the map of the old world, to test the comparative territorial resources of the two states whose armies were now about to come into conflict, the immense preponderance of the material power of the Persian king over that of the Athenian republic is more striking than any similar contrast which history can supply. It has been truly remarked, that, in estimating mere areas, Attica, containing on its whole surface only seven hundred square miles, shrinks into insignificance if compared with many a baronial fief of the Middle Ages, or many a colonial allotment of modern times. Its antagonist, the Persian empire, comprised the whole of modern Asiatic and much of modern European Turkey, the modern kingdom of Persia, and the countries of modern Georgia, Armenia, Balkh, the Punjaub, Affghanistan, Beloochistan, Egypt, and Tripoli.