The next period was one in which the relations of Persia and Greece were largely determined by the exigencies of Greek politics. The two great rivals for supremacy, Athens and Sparta, found Persian help, especially in the shape of gold, very useful; and Persia, for her own purposes, played off the two against each other. There is an amusing scene in Aristophanes which illustrates this state of affairs. A pretended Persian envoy is introduced to the Assembly. He wears a mask which is made of one big eye, in token that he is the King's Eye, and mutters some gibberish which his introducer interprets as a promise to send some gold. The scene goes on:

"Tell them about the gold; speak louder and more plainly."

The Eye spoke again: "Gapey Greeks, gold a fooly jest."

"That is plain enough," cried a man in the Assembly.

Ambassador.     "Well, what do you make of it?"

Citizen.      "Why, that it is a foolish jest for us Greeks to think that we shall get any gold."

Amb.      "You're quite wrong. He didn't say 'jest' but 'chest.' We are to get chests of gold."

Cit. (turning to the Eye).      "Now listen to me; is the king going to send us any gold?" Eye shakes his head.

Cit.      "Are the ambassadors cheating us?" Eye nods.

Cit.      "Well, anyhow the creature knows how to nod in the right way."

This humiliating state of things reached its worst in 387 , when what was called the Peace of Antalcidas was concluded between Persia and Sparta. It is enough to quote one clause from the treaty, which, it should be said, all the Greek States agreed to accept.

"King Artaxerxes thinks it just that the cities in Asia and the islands of Clazomenæ and Cyprus should belong to him. He thinks it just also to have all the other Hellenic cities autonomous, both small and great, except Lemnos, Imbros, and Scyros, which are to belong to Athens as they originally did. Should any parties refuse to accept this peace, I will make war upon them, along with those of the same mind, by land as well as by sea, with ships and with money."

It looked as if all that had been won at Marathon and Salamis had been lost, and Persia had become the arbiter of the fate of Greece. The Asiatic Greeks did lose what had been gained for them, for they fell again under the power of Persia. But these evils worked, in a way, their own cure. The States which had abused their power for selfish purposes fell, one after another, into the background, and others, which had not exhausted themselves in futile struggles for supremacy, came to the front. One of the claims which these new representatives of Greek feeling put forward was the resolve to exact vengeance—for this was the common form which the idea took—for the wrongs which Persia had done to Greece. At the same time there had been various revelations of the real weakness of the gigantic Empire which stretched from the Mediterranean to the Indian Ocean. The Expedition of the Ten Thousand, though it had failed of its immediate object of dethroning one prince in favour of another, had shown the immense superiority of the Greek race over its ancient enemy. Ten thousand men had marched into the very heart of Persia without meeting with a check, and had made their way back again under circumstances of almost incredible difficulty, without suffering anything like disaster.

Jason, tyrant of Pheræ in Thessaly (d. 370 ) was the first, as far as we know, to form a definite scheme for the invasion of Persia. Thessaly I have had occasion but once only to mention. This was in describing the battle of Platæa, when some cavalry from this region did good service to the Persians. It is strange to find in it the first advocate of what we may call the anti-Persian Crusade. But Jason had not the means to carry out so important a scheme. Anyhow, his career was cut short by assassination.

About a quarter of a century later we find the idea further developed. Its exponent is now the greatest rhetorician of the time, and the champion whose services are invoked is Philip of Macedon. About 346 Isocrates addressed a letter to Philip, who had recently been made president of the Amphictyonic Council, suggesting to him that he should reconcile the Greek States to each other and with their help wage war against Persia. The counsel was not offered, we may be sure, without a previous assurance that it would be welcome to the prince to whom it was given. Philip certainly cherished some such purpose. This was the ultimate object which he set before himself in his struggle for supremacy in Greece. He even went so far as to make definite preparations for the enterprise. It may well be doubted whether he had genius enough for so gigantic an enterprise. It was not put to the test. His career also was cut short by the sword of the assassin. He was slain in 336 , in the forty-seventh year of his age. Able as he was, he left to a still abler successor the inheritance of his preparations and his plans.

Alexander, who at his father's death was not quite twenty, had first to consolidate his position. He began by crushing his barbarous neighbours in the north; he then stamped out a rebellion in Greece. This done he turned his attention to preparing his great plan. All was ready in less than two years.

In April, 334, Alexander crossed the Hellespont into Asia. He had about 35,000 men with him, one-seventh being cavalry. Marching slowly eastwards, he came, a few weeks later (May 25th), on the Persian army, which was encamped on the eastern bank of the Granicus, a small stream which flows down from the Ida range into the Sea of Marmora. Of the Persian strength differing accounts are given. The total probably exceeded that of Alexander's army. The proportion of cavalry to infantry was certainly much larger. The front line, indeed, which held the bank of the river, consisted wholly of this arm. On the right were the Medes and Bactrians, wearing the national dress, a round-topped cap, gaily-coloured tunic, and scale armour. In the centre, similarly accoutred, were the Paphlagonians and Hyrcanians; on the right was a small body of Greek horse, and the Persian cavalry proper, largely made up of men who claimed descent from the Seven Deliverers, the little company of nobles who delivered Persia from the sway of the false Smerdis. Here Memnon, the Rhodian, the ablest counsellor of King Darius, was in command. The infantry, both Asiatic and Greek, was posted in reserve, on the rising ground which marked the limit of the winter floods. The river was now flowing within its banks, but with a full, strong stream.

Alexander, who was mounted on his famous charger Bucephalus, rode along the line, addressing a few words of encouragement to each squadron and company as he passed it, and finally placed himself at the head of the right division of the army. As soon as the Persian leaders perceived his intention, they began to reinforce their own left. The fame of the king's personal prowess had not failed to reach them, and they knew that the fiercest struggle would be where he might be in immediate command. Alexander saw the movement and the opportunity which it offered him. He would have his antagonists at a disadvantage if he could catch them in the confusion of a change. Accordingly he ordered the whole line to advance, the right division being thrown somewhat forward. Here was a famous corps d'élite, a heavy cavalry regiment that went under the name of the "Royal Companions." This was the first to enter the river. A number of javelin-throwers and archers, on either side, covered their advance; they were supported by some light horse and a regiment of light infantry.

The van of the attacking force made its way across the stream in fair order. The river-bed was rough, full of great stones brought down by floods and with here and there a dangerously deep hole, but there was no mud or treacherous sand. The first assault was checked. A line of dismounted troopers stood in the water, wherever it was shallow enough to allow it; on the bank itself was a mass of horsemen, two or three files deep. The combatants below plied their swords; those on the higher ground showered javelins on the advancing foe. Only a few of these could struggle up the somewhat steep bank; of the few some were slain, others thrust back upon the troops that followed them. The attack seemed to have failed. But when the king himself took up the attack the fortunes of the day were rapidly changed. For the first of many times throughout his marvellous career the personal courage of Alexander, his strength, his dexterity in arms, turned the tide of battle. He was a matchless soldier as well as a matchless general, and seemed to combine the old soldiership and the new, the personal prowess of an Achilles and the tactical skill of an Epaminondas. He sprang forward, rallying, as he advanced, his disheartened troops, struck down adversary after adversary, and climbed the bank with astonishing agility. The example of such a leader seemed to give the Companions an irresistible strength. In a few minutes the bank of the Granicus was won. But the battle was not yet over. The Persians had been beaten back from their first line of defence; but they still held the level ground, and till the whole of the Greek army had crossed the stream they had a great superiority in numbers, enabling them to deliver charges which the weight of men and horses might well have made irresistible. Again Alexander was in the thick of the conflict. His pike had been broken in the struggle for the bank. He asked his orderly for another. The man showed him his own broken weapon. Then the king looked round to his followers, holding high the splintered shaft. The appeal was answered in an instant. It was a Corinthian, Demaratus by name, who answered his call and supplied him with a fresh lance. It was not done a moment too soon. The Persian cavalry charged in a heavy column, its leader, Mithradates, son-in-law to King Darius, riding a long way in front of his men. Alexander spurred his horse, charged at Mithradates with levelled pike, struck him in the face, and hurled him dying to the ground. Meanwhile another Persian noble had ridden up. He struck a fierce blow at Alexander with his scymetar, but missing his aim in his excitement, did nothing more than shear off the crest of the helmet. Alexander replied with a thrust which broke through his breastplate and inflicted a mortal wound. There was a third antagonist behind, but his arm was severed by a sword-cut from a Macedonian officer just as he was in the act of delivering a blow. The struggle, however, was continued with unabated fury. It was not till almost every leader had fallen that the Persian cavalry gave way.

Elsewhere in the field the victory was more easily won. The elite of the Persian army had been brought together to oppose Alexander, and the remainder did not hold their ground with equal tenacity. When the phalanx had made its way across the river, and reformed itself again on the eastern bank, it encountered no opposition.

There still remained, however, a force to be dealt with which, had it been properly handled, might have been found a serious difficulty for the conquerors. The infantry, as has been said, was posted in reserve, and of this force not less than a half, numbering as many as ten thousand, consisted of Greek mercenaries. These had remained in absolute inaction, idly watching the struggle on the level ground below. They had no responsible leaders; no orders had been issued to them. The Persian generals, confident in the strength of their special arm, the cavalry, neglected to make any use of this invaluable force. And yet they might have known what ten thousand Greeks, well led, could do! Alexander came up and charged the unprotected flank of the Greek force. "He had the defects of his virtues," and was too eager in "drinking the delight of battle." His charger—not the famous Bucephalus, which had fallen lame, but another horse—was killed under him. The light infantry also delivered an attack, but the mercenaries still held their ground. But when the phalanx came up, their strength or their courage failed. The front ranks were crushed by the advance of the ponderous machine, and the rest first wavered, then broke up in hopeless confusion. Not less than half of their number were killed in their places or in the attempt to escape. The rest were either admitted to quarter, or contrived to make their way to some place of safety.