=146.= The Spartans were still too much absorbed in the siege of Ithome to interfere with the great and sudden advancement of Athenian power; but a disaster which befell their little ancestral land of Doris, in war with the Phocians, withdrew their attention even from their own troubles. An army of 1,500 heavy-armed Spartans and 10,000 auxiliaries, sent to the relief of the Dorians, drove the Phocians from the town they had taken, and secured their future good behavior by a treaty. The retreat of the Spartans was now cut off by the Athenian fleet in the Gulf of Corinth and the garrison in the Megarid. Their commander, Nicome´des, had, however, reasons beyond the necessity of the case for remaining a while in Bœotia. He was plotting with the aristocratic party in Athens for the return of Cimon, and he also desired to increase the power of Thebes, as a near and dangerous rival to the former city. [Sidenote: B. C. 457.] The conspiracy becoming known, the Athenians were roused to revenge. They raised an army of 14,000 men and marched against Nicomedes, at Tan´agra. Both sides fought with equal bravery and skill, and the victory was undecided until the Thessalian cavalry deserted to the Spartans. The Athenians and their allies still held out for some hours, but when the contest ended with the daylight, the victory remained with their adversaries. Nicomedes reaped no other fruit from his victory than a safe return home, but Thebes gained from it an increase of power over the cities of Bœotia. [Sidenote: B. C. 456.] =147.= BATTLE OF ŒNO´PHYTA. The Athenians were only spurred to fresh exertions. The brave Myronides entered Bœotia two months after the battle of Tanagra, and gained at Œnophyta one of the most decisive victories ever achieved by Greeks. The walls of Tanagra were leveled with the ground. Phocis, Locris, and all Bœotia, except Thebes, were brought into alliance with Athens. These alliances were rendered effective by the establishment of free governments in all the towns, which, for self-preservation, must always range themselves on the side of Athens; so that Myronides could boast that he had not only subdued enemies, but filled central Greece with garrisons of friends. [Sidenote: B. C. 455.] =148.= Soon after the completion of the Long Walls, in 456, the island of Ægina submitted at last to Athens. Her shipping was surrendered, her walls destroyed, and the life-long rival became a tributary and subject. A fleet of fifty Athenian vessels, commanded by Tol´mides, cruised around the Peloponnesus; burned Gyth´ium, a port of Sparta; captured Chalcis, in Ætolia, which belonged to Corinth, and defeated the Sicyonians on their own coast. Returning through the Corinthian Gulf, they captured Naupac´tus, in western Locris, and all the cities of Cephallenia.