a Syracusan, son of Hipparnus, famous for his power and abilities. He was related to Dionysius, and often, along with the philosopher Plato, who had come to reside at the tyrant's court, advised him to lay aside the supreme power. But his great popularity rendered him odious in the eyes of the tyrant, who banished him to Greece. There, however, he collected a numerous force, and resolved to free his country from tyranny; an achievement which he easily effected, on account of his uncommon popularity. He entered the port of Syracuse with only two ships, and in three days reduced under his power an empire which had already subsisted for fifty years, and which was guarded by five hundred ships of war, and above a hundred thousand troops. The tyrant fled to Corinth, and Dion kept the power in his own hands, fearful of the aspiring ambition of some of the friends of Dionysius; but he was shamefully betrayed and murdered by one of his familiar friends, called Callicrates or Callipus, 354 years before the Christian era.

DION Cassius, a native of Nicaea, in Bithynia, whose father's name was Aprianus. He was raised to the greatest offices of state in the Roman empire by Pertinax, and his three successors. Being naturally fond of study, he improved himself by unrewarded application, and spent ten years in collecting materials for a history of Rome, which he published in eighty books; after a laborious employment of twelve years in composing it. This valuable history commenced with the arrival of Æneas in Italy, and extended to the reign of the Emperor Alexander Severus. The first thirty-four books are totally lost; the twenty following, that is, from the thirty-fifth to the fifty-fourth, remain entire; the six following are mutilated; and fragments are all that we possess of the last twenty. In the compilation of this extensive history, Dion proposed to himself Thucydides as a model, but he is not perfectly happy in his imitation. His style is pure and elegant, his narrations are judiciously managed, and his reflections are generally learned; but, upon the whole, he is credulous, and the bigoted slave of partiality, satire, and flattery. He inveighs against the republican principles of Brutus and Cicero, and extols the cause of Caesar. Seneca is the object of his satire, and is represented by the historian as debauched and licentious in his morals.