But the Spartan Empire was also the cause of the rise of another power, much stronger than the new Athenian alliance, and more strikingly illustrative of the growing weakness of the individual πόλις. In Bœotia there had always been a league of cities, and the physical conditions of the district seemed to make a real federal union more possible here than elsewhere in Greece proper. Bœotia was full of cities, which were not separated from each other by great mountain chains; but one of these cities, Thebes, was larger, stronger, and more renowned than the rest. A true federation of equals was therefore here again impossible; and as Professor Freeman has suggested, a συνοικισμός with Thebes, like that of the Attic communities with Athens, would have been a more practicable form of union.[1] But the other Bœotian towns were probably much stronger than the village communities of Attica, and a loose federal union was the utmost they would bear. Of the constitution of this union we know very little; but the one indisputable fact in it is that Thebes constituted a centralising tendency which was apt to irritate the other cities, and drove Platæa and Thespiæ into the arms of Athens.[2]
It is obvious that under pressure of a common danger this centralising tendency of Thebes would rapidly gain ground. Thebes had missed her chance in the Persian wars by ignobly taking the side of
