Eurybătus in Harpers Dictionary of Classical Antiquities

（Εὐρύβατος). An Ephesian, whom Croesus sent with a large sum of money to the Peloponnesus to hire mercenaries for him in his war with Cyrus. He, however, deserted to Cyrus, and betrayed the whole matter to him. In consequence of this treachery his name passed into a proverb among the Greeks (in Ctes. 43).

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