Eurybatus
2. 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, went over to Cyrus, and betrayed the whole matter to him. In consequence of this treachery, his name passed into a proverb amongst the Greeks. (Diod. Excerpt. de Virt. et Vit. p. 553; Ulpian, in Dem. de Coron. p. 137; Aeschin. in Ctes. 100.43; Plat. Protag. p. 327.)
From William Smith (ed.), Dictionary of Greek and Roman Biography and Mythology. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.