Sparta had not become the head of this league by agreement, and still less by usurpation; but by tacit acknowledgment she was the leader, not only of this, but of the whole of Greece; and she acted as such in all foreign relations from about the year 580 B.C. Her alliance was courted by Crœsus: and the Ionians, when pressed by Cyrus, had recourse to the Spartans, who, with an amusing ignorance of the state of affairs beyond the sea, thought to terrify the king of Persia by the threat of hostilities. It is a remarkable fact, that there were at that time Scythian envoys in Sparta, with whom a great plan of operations against Persia is said to have been concerted. In the year 520 B.C. the Platæans put themselves under the protection of Cleomenes, who referred them to Athens; a herald from Sparta drove the Alcmæonidæ from their city: afterwards Aristagoras sought from the protector of Greece aid against the national enemy: and when the Æginetans gave the Persians earth and water, the Athenians accused them of treachery before the Spartans: and lastly, during the Persian War, Greece found in the high character of that state the only means of effecting the union so necessary for her safety and success. In this war a new confederacy was formed, which was extended beyond the Peloponnese; the community of danger and of victory having, besides a momentary combination, also produced a union destined for some duration. It was the assembly of this league--a fixed congress at Corinth during, and at Sparta after, the war--that settled the internal differences of Greece, that invited Argos, Corcyra, and Gelo to join the league, and afterwards called upon Themistocles to answer for his proceedings. So much it did for the present emergency. But at the same time Pausanias, the regent of Sparta, after the great victory of Platæa, prevailed upon the allies to conclude a further treaty. Under the auspices of the gods of the confederacy, particularly of the Eleutherian (or Grecian) Jupiter, they pledged themselves mutually to maintain the independence of all states, and to many other conditions, of which the memory has been lost. To the Platæans in particular security from danger was promised. The Ionians also, after the battle of Mycale, were received into this confederacy.