In this so-called first Peloponnesian War Sparta herself took but a small share beyond helping to inflict a defeat on the Athenians at Tanagra in 457 B.C. After this battle they concluded a truce, which gave the Athenians an opportunity of taking their revenge on the Boeotians at the battle of Oenophyta, of annexing to their empire Boeotia, Phocis and Locris, and of subjugating Aegina.
In Greece itself meanwhile the opposition to Sparta was growing increasingly powerful, and, though at Coronea Agesilaus had slightly the better of the Boeotians and at Corinth the Spartans maintained their position, yet they felt it necessary to rid themselves of Persian hostility and if possible use the Persian power to strengthen their own position at home: they therefore concluded with Artaxerxes II.
It was originally composed of twelve tribes dwelling round Thermopylae - the Thessalians, Boeotians, Dorians, Ionians, Perrhaebians, Magnetes, Locrians, Oetaeans, Phthiotes, Malians, Phocians (Aeschin.
It was this motive which first induced the Thessalians to leave their home in Epirus and descend into this district, and from this movement arose the expulsion of the Boeotians from Arne, and their settlement in the country subsequently called Boeotia; while another wave of the same tide drove the Dorians also southward, whose migrations changed the face of the Peloponnese.
The central position and military security of the city naturally tended to raise it to a commanding position among the Boeotians, and from early days its inhabitants endeavoured to establish a complete supremacy over their kinsmen in the outlying towns.