The long existing jealousy of Sparta at last broke out in open hostilities. While the siege of Ithome was in progress, Sparta, still powerful in her alliances, sent her allied forces into Bœotia to counteract the growing influence of the Athenians in that quarter. The indignant Athenians, led by Pericles, marched out to meet them, but were worsted in the battle of Tan'agra. Before this conflict began, Cimon, the banished commander, appeared in the Athenian camp and begged permission to enter the ranks against the enemy. His request being refused, he left his armor with his friends, of whom there were one hundred among the Athenians, with the charge to refute, by their valor, the accusation that he and they were the friends of Sparta. Everyone of the one hundred fell in the conflict. About two months after, in the early part of the year 456 B.C., the Athenians wiped off the stain of their defeat at Tanagra by a victory over the combined Theban and Bœotian forces, then in alliance with Sparta; whereby the authority and influence of Sparta were again confined to the Peloponnesus. The Athenians were now masters of Greece, from the Gulf of Corinth to the Pass of Thermopylæ, and in the following year they sent an expedition round the Peloponnesus, which captured, among other cities, Naupactus, on the Corinthian Gulf. The third and last Messenian war had just been concluded by the surrender of Ithome, on terms which permitted the Messenians and their families to retire from the Peloponnesus, and they joined the colony which Athens planted at Naupactus. But the successes of Athens in Greece were counterbalanced, in the same year, by reverses in Egypt, where the Athenians were fighting Persia in aid of In'arus, a Libyan prince. These, with some other minor disasters, and the state of bitter feeling that existed between the two parties at Athens, induced Pericles to recall Cimon from exile and put him in command of an expedition against Cyprus and Egypt. In 449, however, Cimon was taken ill, and he died in the harbor of Ci'tium, to which place he was laying siege. Before the death of Cimon, and through his intervention, a five years' truce had been concluded with Sparta, and soon after his death peace was made with Persia. From this time the empire of Athens began to decline. In the year 447 B.C. a revolt in Bœotia resulted in the overthrow of Athenian supremacy there, while the expulsion of the Athenians from Pho'cis and Lo'cris, and the revolt of Euboea and Megara, followed soon after. The revolt of Euboea was soon quelled, but this was the only success that Athens achieved. Meanwhile a Spartan army invaded Attica and marched to the neighborhood of Eleusis. Having lost much of her empire, with a fair prospect of losing all of it if hostilities continued, Athens concluded a thirty years' truce with Sparta and her allies, by the terms of which she abandoned her conquests in the Peloponnesus, and Megara became an ally of Sparta (445 B.C.)