All this took place while Xerxes was slowly advancing from Sardis to the Hellespont, and from the Hellespont to Doriscus, as described in the preceding chapter.
The council resolved on dispatching an embassy at once to all the states of Greece, as well as to some of the remoter neighboring powers, asking them to join the alliance.
The first Greek city to which these embassadors came was Argos, which was the capital of a kingdom or state lying between Athens and Sparta, though within the Peloponnesus. The states of Argos and of Sparta, being neighbors, had been constantly at war. Argos had recently lost six thousand men in a battle with the Spartans, and were, consequently, not likely to be in a very favorable mood for a treaty of friendship and alliance.
When the embassadors had delivered their message, the Argolians replied that they had anticipated such a proposal from the time that they had heard that Xerxes had commenced his march toward Greece, and that they had applied, accordingly, to the oracle at Delphi, to know what it would be best for them to do in case the proposal were made. The answer of the oracle had been, they said, unfavorable to their entering into an alliance with the Greeks. They were willing, however, they added, notwithstanding this, to enter into an alliance, offensive and defensive, with the Spartans, for thirty years, on condition that they should themselves have the command of half the Peloponnesian troops. They were entitled to the command of the whole, being, as they contended, the superior nation in rank, but they would waive their just claim, and be satisfied with half, if the Spartans would agree to that arrangement.
The Spartans replied that they could not agree to those conditions. They were themselves, they said, the superior nation in rank, and entitled to the whole command; and as they had two kings, and Argos but one, there was a double difficulty in complying with the Argive demand. They could not surrender one half of the command without depriving one of their kings of his rightful power.
Thus the proposed alliance failed entirely, the people of Argos saying that they would as willingly submit to the dominion of Xerxes as to the insolent demands and assumptions of superiority made by the government of Sparta.
The embassadors among other countries which they visited in their attempts to obtain alliance and aid, went to Sicily. Gelon was the King of Sicily, and Syracuse was his capital. Here the same difficulty occurred which had broken up the negotiations at Argos. The embassadors, when they arrived at Syracuse, represented to Gelon that, if the Persians subdued Greece, they would come to Sicily next, and that it was better for him and for his countrymen that they should meet the enemy while he was still at a distance, rather than to wait until he came near. Gelon admitted the justice of this reasoning, and said that he would furnish a large force, both of ships and men, for carrying on the war, provided that he might have the command of the combined army. To this, of course, the Spartans would not agree. He then asked that he might command the fleet, on condition of giving up his claim to the land forces. This proposition the Athenian embassadors rejected, saying to Gelon that what they were in need of, and came to him to obtain, was a supply of troops, not of leaders. The Athenians, they said, were to command the fleet, being not only the most ancient nation of Greece, but also the most immediately exposed to the invasion, so that they were doubly entitled to be considered as the principals and leaders in the war.
Gelon then told the embassadors that, since they wished to obtain every thing and to concede nothing, they had better leave his dominions without delay, and report to their countrymen that they had nothing to expect from Sicily.
The embassadors went then to Corcyra, a large island on the western coast of Greece, in the Adriatic Sea. It is now called Corfu. Here they seemed to meet with their first success. The people of Corcyra acceded to the proposals made to them, and promised at once to equip and man their fleet, and send it round into the Ægean Sea. They immediately engaged in the work, and seemed to be honestly intent on fulfilling their promises. They were, however, in fact, only pretending. They were really undecided which cause to espouse, the Greek or the Persian, and kept their promised squadron back by means of various delays, until its aid was no longer needed.
But the most important of all these negotiations of the Athenians and Spartans with the neighboring states were those opened with Thessaly. Thessaly was a kingdom in the northern part of Greece. It was, therefore, the territory which the Persian armies would first enter, on turning the northwestern corner of the Ægean Sea. There were, moreover, certain points in its geographical position, and in the physical conformation of the country, that gave it a peculiar importance in respect to the approaching conflict.
By referring to the map placed at the commencement of the fifth chapter, it will be seen that Thessaly was a vast valley, surrounded on all sides by mountainous land, and drained by the River Peneus and its branches. The Peneus flows eastwardly to the Ægean Sea, and escapes from the great valley through a narrow and romantic pass lying between the Mountains Olympus and Ossa. This pass was called in ancient times the Olympic Straits, and a part of it formed a romantic and beautiful glen called the Vale of Tempe. There was a road through this pass, which was the only access by which Thessaly could be entered from the eastward.
To the south of the Vale of Tempe, the mountains, as will appear from the map, crowded so hard upon the sea as not to allow any passage to the eastward of them. The natural route of Xerxes, therefore, in descending into Greece, would be to come down along the coast until he reached the mouth of the Peneus, and then, following the river up through the Vale of Tempe into Thessaly, to pass down toward the Peloponnesus on the western side of Ossa and Pelion, and of the other mountains near the sea. If he could get through the Olympic Straits and the Vale of Tempe, the way would be open and unobstructed until he should reach the southern frontier of Thessaly, where there was another narrow pass leading from Thessaly into Greece. This last defile was close to the sea, and was called the Straits of Thermopylæ.
Thus Xerxes and his hosts, in continuing their march to the southward, must necessarily traverse Thessaly, and in doing so they would have two narrow and dangerous defiles to pass-one at Mount Olympus, to get into the country, and the other at Thermopylæ, to get out of it. It consequently became a point of great importance to the Greeks to determine at which of these two passes they should make their stand against the torrent which was coming down upon them.
This question would, of course, depend very much upon the disposition of Thessaly herself. The government of that country, understanding the critical situation in which they were placed, had not waited for the Athenians and Spartans to send embassadors to them, but, at a very early period of the war-before, in fact, Xerxes had yet crossed the Hellespont, had sent messengers to Athens to concert some plan of action. These messengers were to say to the Athenians that the government of Thessaly were expecting every day to receive a summons from Xerxes, and that they must speedily decide what they were to do; that they themselves were very unwilling to submit to him, but they could not undertake to make a stand against his immense host alone; that the southern Greeks might include Thessaly in their plan of defense, or exclude it, just as they thought best. If they decided to include it, then they must make a stand at the Olympic Straits, that is, at the pass between Olympus and Ossa; and to do that, it would be necessary to send a strong force immediately to take possession of the pass. If, on the contrary, they decided not to defend Thessaly, then the pass of Thermopylæ would be the point at which they must make their stand, and in that case Thessaly must be at liberty to submit on the first Persian summons.