(M386) In order to guard against the ascendency of tyrants—the great evil of the ancient States, Cleisthenes devised the institution of _ostracism_, by which a suspected or obnoxious citizen could be removed from the city for ten years, though practically abridged to five. It simply involved an exclusion from political power, without casting a stigma on the character. It was virtually a retirement, during which his property and rights remained intact, and attended with no disgrace. The citizens, after the senate had decreed the vote was needful, were required to write a name in an oyster shell, and he who had less than six thousand votes was obliged to withdraw within ten days from the city. The wisdom of this measure is proved in the fact that no tyrannical usurpation occurred at Athens after that of Pisistratus. This revolution which Cleisthenes effected was purely democratic, to which the aristocrats did not submit without a struggle. The aristocrats called to their aid the Spartans, but without other effect than creating that long rivalry which existed between democracy and oligarchy in Greece, in which Sparta and Athens were the representatives. About this time began the dominion of Athens over the islands of the Ægean and the system of colonizing conquered States, This was the period which immediately preceded the Persian wars, when Athens reached the climax of political glory. (M387) Next in importance to the States which have been briefly mentioned was Bœotia, which contained fourteen cities, united in a confederacy, of which Thebes took the lead. They were governed by magistrates, called bœtarchs, elected annually. In these cities aristocratic institutions prevailed. The people were chiefly of Æolian descent, with a strong mixture of the Dorian element, and were dull and heavy, owing, probably, to the easy facilities of support, in consequence of the richness of the soil. (M388) At the west of Bœotia, Phocis, with its small territory, gained great consideration from the possession of the Delphic oracle; but its people thus far, of Achæan origin, played no important part in the politics of Greece. (M389) North of the isthmus lay the extensive plains of Thessaly, inclosed by lofty mountains. Nature favored this State more than any other in Greece for political pre-eminence, but inhabitants of Æolian origin were any thing but famous. At first they were governed by kings, but subsequently an aristocratic government prevailed. They were represented in the Amphictyonic Council. (M390) The history of Macedonia is obscure till the time of the Persian wars; but its kings claimed an Heraclid origin. The Doric dialect predominated in a rude form. (M391) Epirus, west of Thessaly and Macedonia, was inhabited by various tribes, under their own princes, until the kings of Molossus, claiming descent from Achilles, founded the dynasty which was so powerful under Pyrrus.