No doubt the Greeks viewed with deep alarm this formidable progress. They had never yet directly measured arms with the Persians, and dreaded them more than, as was afterwards shown, they had reason to. But at Mount Athos the deities of the winds came to their aid. As the fleet was rounding that promontory, often fatal to mariners, a frightful hurricane swooped upon it, and destroyed three hundred of its ships, while no less than twenty thousand men became victims of the waves. Some of the crews reached the shores, but of these many died of cold, and others were slain and devoured by wild beasts, which roamed in numbers on that uninhabited point of land. The land army, too, lost heavily from the hurricane; and Mardonius, fearing to advance farther after this disaster, ingloriously made his way back to the Hellespont. So ended the first invasion of Greece. Three years afterwards another was made. Darius, indeed, first sent heralds to Greece, demanding _earth and water_ in token of submission to his will. To this demand some of the cities cowardly yielded; but Athens, Sparta, and others sent back the heralds with no more earth than clung to the soles of their shoes. And so, as Greece was not to be subdued through terror of his name, the great king prepared to make it feel his power and wrath, incited thereto by his hatred of Athens, which Hippias took care to keep alive. Another expedition was prepared, and put under the command of another general, Datis by name. The army was now sent by a new route. Darius himself had led his army across the Bosphorus, where Constantinople now stands, and where Byzantium then stood. Mardonius conveyed his across the southern strait, the Hellespont. The third expedition was sent on shipboard directly across the sea, landing and capturing the islands of the AEgean as it advanced. Landing at length on the large island of Euboea, near the coast of Attica, Datis stormed and captured the city of Eretria, burnt its temples, and dragged its people into captivity. Then, putting his army on shipboard again, he sailed across the narrow strait between Euboea and Attica, and landed on Attic soil, in the ever-memorable Bay of Marathon. It seemed now, truly, as if Darius was about to gain his wish and revenge himself on Athens. The plain of Marathon, where the great Persian army had landed and lay encamped, is but twenty-two miles from Athens by the nearest road,--scarcely a day's march. The plain is about six miles long, and from a mile and a half to three miles in width, extending back from the sea-shore to the rugged hills and mountains which rise to bind it in. A brook flows across it to the sea, and marshes occupy its ends. Such was the field on which one of the decisive battles of the world was about to be fought. [Illustration: RUINS OF THE PARTHENON.]