With the exception of the Chinese empire, in which, throughout all ages down to the last few years, one-third of the human race has dwelt almost unconnected with the other portions, all the great kingdoms which we know to have existed in Ancient Asia, were, in Darius's time, blended with the Persian. The northern Indians, the Assyrians, the Syrians, the Babylonians, the Chaldees, the Phoenicians, the nations of Palestine, the Armenians, the Bactrians, the Lydians, the Phrygians, the Parthians, and the Medes,—all obeyed the sceptre of the Great King: the Medes standing next to the native Persians in honour, and the empire being frequently spoken of as that of the Medes, or as that of the Medes and Persians. Egypt and Cyrene were Persian provinces; the Greek colonists in Asia Minor and the islands of the AEgean were Darius's subjects; and their gallant but unsuccessful attempts to throw off the Persian yoke had only served to rivet it more strongly, and to increase the general belief: that the Greeks could not stand before the Persians in a field of battle. Darius's Scythian war, though unsuccessful in its immediate object, had brought about the subjugation of Thrace and the submission of Macedonia. From the Indus to the Peneus, all was his.

We may imagine the wrath with which the lord of so many nations must have heard, nine years before the battle of Marathon, that a strange nation towards the setting sun, called the Athenians, had dared to help his rebels in Ionia against him, and that they had plundered and burnt the capital of one of his provinces. Before the burning of Sardis, Darius seems never to have heard of the existence of Athens; but his satraps in Asia Minor had for some time seen Athenian refugees at their provincial courts imploring assistance against their fellow-countrymen. When Hippias was driven away from Athens, and the tyrannic dynasty of the Pisistratidae finally overthrown in 510 B.C., the banished tyrant and his adherents, after vainly seeking to be restored by Spartan intervention, had betaken themselves to Sardis, the capital city of the satrapy of Artaphernes. There Hippias (in the expressive words of Herodotus) [Herod. lib. v. c. 96.] began every kind of agitation, slandering the Athenians before Artaphernes, and doing all he could to induce the satrap to place Athens in subjection to him, as the tributary vassal of King Darius. When the Athenians heard of his practices, they sent envoys to Sardis to remonstrate with the Persians against taking up the quarrel of the Athenian refugees. But Artaphernes gave them in reply a menacing command to receive Hippias back again if they looked for safety. The Athenians were resolved not to purchase safety at such a price; and after rejecting the satrap's terms, they considered that they and the Persians were declared enemies. At this very crisis the Ionian Greeks implored the assistance of their European brethren, to enable them to recover their independence from Persia. Athens, and the city of Eretria in Euboea, alone consented. Twenty Athenian galleys, and five Eretrian, crossed the AEgean Sea; and by a bold and sudden march upon Sardis the Athenians and their allies succeeded in capturing the capital city of the haughty satrap, who had recently menaced them with servitude or destruction. The Persian forces were soon rallied, and the Greeks were compelled to retire. They were pursued, and defeated on their return to the coast, and Athens took no further part in the Ionian war. But the insult that she had put upon the Persian power was speedily made known throughout that empire, and was never to be forgiven or forgotten. In the emphatic simplicity of the narrative of Herodotus, the wrath of the Great King is thus described:—"Now when it was told to King Darius that Sardis had been taken and burnt by the Athenians and Ionians, he took small heed of the Ionians, well knowing who they were, and that their revolt would soon be put down: but he asked who, and what manner of men, the Athenians were. And when he had been told, he called for his bow; and, having taken it, and placed an arrow on the string, he let the arrow fly towards heaven; and as he shot it into the air, he said, 'O Supreme God! grant me that I may avenge myself on the Athenians.' And when he had said this, he appointed one of his servants to say to him every day as he sat at meat, 'Sire, remember the Athenians.'"

Some years were occupied in the complete reduction of Ionia. But when this was effected, Darius ordered his victorious forces to proceed to punish Athens and Eretria, and to conquer European Greece. The first armament sent for this purpose was shattered by shipwreck, and nearly destroyed off Mount Athos, But the purpose of King Darius was not easily shaken. A larger army was ordered to be collected in Cilicia; and requisitions were sent to all the maritime cities of the Persian empire for ships of war, and for transports of sufficient size for carrying cavalry as well as infantry across the AEgean. While these preparations were being made, Darius sent heralds round to the Grecian cities demanding their submission to Persia. It was proclaimed in the market-place of each little Hellenic state (some with territories not larger than the Isle of Wight), that King Darius, the lord of all men, from the rising to the setting sun, required earth and water to be delivered to his heralds, as a symbolical acknowledgment that he was head and master of the country. [Aeschines in Ctes. p. 622, ed. Reiske. Mitford, vol. i. p. 485. AEschines is speaking of Xerxes, but Mitford is probably right in considering it as the style of the Persian kings in their proclamations. In one of the inscriptions at Persepolis, Darius terms himself "Darius the great king, king of kings, the king of the many peopled countries, the supporter also of this great world." In another, he styles himself "the king of all inhabited countries." (See "Asiatic Journal" vol. X pp. 287 and 292, and Major Rawlinson's Comments.)] Terror-stricken at the power of Persia and at the severe punishment that had recently been inflicted on the refractory Ionians, many of the continental Greeks and nearly all the islanders submitted, and gave the required tokens of vassalage. At Sparta and Athens an indignant refusal was returned: a refusal which was disgraced by outrage and violence against the persons of the Asiatic heralds.

Fresh fuel was thus added to the anger of Darius against Athens, and the Persian preparations went on with renewed vigour. In the summer of 490 B.C., the army destined for the invasion was assembled in the Aleian plain of Cilicia, near the sea. A fleet of six hundred galleys and numerous transports was collected on the coast for the embarkation of troops, horse as well as foot. A Median general named Datis, and Artaphernes, the son of the satrap of Sardis, and who was also nephew of Darius, were placed in titular joint command of the expedition. That the real supreme authority was given to Datis alone is probable, from the way in which the Greek writers speak of him. We know no details of the previous career of this officer; but there is every reason to believe that his abilities and bravery had been proved by experience, or his Median birth would have prevented his being placed in high command by Darius. He appears to have been the first Mede who was thus trusted by the Persian kings after the overthrow of the conspiracy of the Median Magi against the Persians immediately before Darius obtained the throne. Datis received instructions to complete the subjugation of Greece, and especial orders were given him with regard to Eretria and Athens. He was to take these two cities; and he was to lead the inhabitants away captive, and bring them as slaves into the presence of the Great King.

Datis embarked his forces in the fleet that awaited them; and coasting along the shores of Asia Minor till he was off Samos, he thence sailed due westward through the AEgean Sea for Greece, taking the islands in his way. The Naxians had, ten years before, successfully stood a siege against a Persian armament, but they now were too terrified to offer any resistance, and fled to the mountain-tops, while the enemy burnt their town and laid waste their lands. Thence Datis, compelling the Greek islanders to join him with their ships and men, sailed onward to the coast of Euboea. The little town of Carystus essayed resistance, but was quickly overpowered. He next attacked Eretria. The Athenians sent four thousand men to its aid. But treachery was at work among the Eretrians; and the Athenian force received timely warning from one of the leading men of the city to retire to aid in saving their own country, instead of remaining to share in the inevitable destruction of Eretria. Left to themselves, the Eretrians repulsed the assaults of the Persians against their walls for six days; on the seventh day they were betrayed by two of their chiefs and the Persians occupied the city. The temples were burnt in revenge for the burning of Sardis, and the inhabitants were bound and placed as prisoners in the neighbouring islet of AEgylia, to wait there till Datis should bring the Athenians to join them in captivity, when both populations were to be led into Upper Asia, there to learn their doom from the lips of King Darius himself.

Flushed with success, and with half his mission thus accomplished, Datis reimbarked his troops, and crossing the little channel that separates Euboea from the mainland, he encamped his troops on the Attic coast at Marathon, drawing up his galleys on the shelving beach, as was the custom with the navies of antiquity. The conquered islands behind him served as places of deposit for his provisions and military stores. His position at Marathon seemed to him in every respect advantageous; and the level nature of the ground on which he camped was favourable for the employment of his cavalry, if the Athenians should venture to engage him. Hippias, who accompanied him, and acted as the guide of the invaders, had pointed out Marathon as the best place for a landing, for this very reason. Probably Hippias was also influenced by the recollection, that forty-seven years previously he, with his father Pisistratus, had crossed with an army from Eretria to Marathon, and had won an easy victory over their Athenian enemies on that very plain, which had restored them to tyrannic power. The omen seemed cheering. The place was the same; but Hippias soon learned to his cost how great a change had come over the spirit of the Athenians.

But though "the fierce democracy" of Athens was zealous and true against foreign invader and domestic tyrant, a faction existed in Athens, as at Eretria, of men willing to purchase a party triumph over their fellow-citizens at the price of their country's ruin. Communications were opened between these men and the Persian camp, which would have led to a catastrophe like that of Eretria, if Miltiades had not resolved, and had not persuaded his colleagues to resolve, on fighting at all hazards.

When Miltiades arrayed his men for action, he staked on the arbitrement of one battle not only the fate of Athens, but that of all Greece; for if Athens had fallen, no other Greek state, except Lacedaemon, would have had the courage to resist; and the Lacedaemonians, though they would probably have died in their ranks to the last man, never could have successfully resisted the victorious Persians, and the numerous Greek troops, which would have soon marched under the Persian satraps, had they prevailed over Athens.

Nor was there any power to the westward of Greece that could have offered an effectual opposition to Persia, had she once conquered Greece, and made that country a basis for future military operations. Rome was at this time in her season of utmost weakness. Her dynasty of powerful Etruscan kings had been driven out, and her infant commonwealth was reeling under the attacks of the Etruscans and Volscians from without, and the fierce dissensions between the patricians and plebeians within. Etruria, with her Lucumos and serfs, was no match for Persia. Samnium had not grown into the might which she afterwards put forth: nor could the Greek colonies in South Italy and Sicily hope to survive when their parent states had perished. Carthage had escaped the Persian yoke in the time of Cambyses, through the reluctance of the Phoenician mariners to serve against their kinsmen. But such forbearance could not long have been relied on, and the future rival of Rome would have become as submissive a minister of the Persian power as were the Phoenician cities themselves. If we turn to Spain, or if we pass the great mountain chain which, prolonged through the Pyrenees, the Cevennes, the Alps, and the Balkan, divides Northern from Southern Europe, we shall find nothing at that period but mere savage Finns, Celts, Slaves, and Teutons. Had Persia beaten Athens at Marathon, she could have found no obstacle to prevent Darius, the chosen servant of Ormuzd, from advancing his sway over all the known Western races of mankind. The infant energies of Europe would have been trodden out beneath universal conquest; and the history of the world, like the history of Asia, would have become a mere record of the rise and fall of despotic dynasties, of the incursions of barbarous hordes, and of the mental and political prostration of millions beneath the diadem, the tiara, and the sword.

Great as the preponderance of the Persian over the Athenian power at that crisis seems to have been, it would be unjust to impute wild rashness to the policy of Miltiades, and those who voted with him in the Athenian council of war, or to look on the after-current of events as the mere result of successful indiscretion, as before has been remarked, Miltiades, whilst prince of the Chersonese, had seen service in the Persian armies; and he knew by personal observation how many elements of weakness lurked beneath their imposing aspect of strength. He knew that the bulk of their troops no longer consisted of the hardy shepherds and mountaineers from Persia Proper and Kurdistan, who won Cyrus's battles: but that unwilling contingents from conquered nations now largely filled up the Persian muster rolls, fighting more from compulsion than from any zeal in the cause of their masters. He had also the sagacity and the spirit to appreciate the superiority of the Greek armour and organization over the Asiatic, notwithstanding former reverses. Above all, he felt and worthily trusted the enthusiasm of the men under his command.