Wikipedia
Charidemus , of Oreus in Euboea, was a Greek mercenary leader of the 4th century BC.
About 367 BC, he fought under the Athenian general Iphicrates against Amphipolis. Being ordered by Iphicrates to take the Amphipolitan hostages to Athens, he allowed them to return to their own people, and joined Cotys, king of Thrace, against Athens.
Soon afterwards he fell into the hands of the Athenians and accepted the offer of Timotheus to re-enter their service. Having been dismissed by Timotheus (362 BC) he joined the revolted satraps Memnon and Mentor in Asia, but soon lost their confidence, and was obliged to seek the protection of the Athenians. Finding, however, that he had nothing to fear from the Persians, he again joined Cotys, on whose murder he was appointed guardian to his youthful son Cersobleptes.
In 357 BC, on the arrival of Chares with considerable forces, the Chersonese was restored to Athens. The supporters of Charidemus represented this as due to his efforts, and, in spite of the opposition of Demosthenes, he was honored with a golden crown and the franchise of the city. It was further resolved that his person should be inviolable.
In 351 BC, he commanded the Athenian forces in the Chersonese against Philip II of Macedon, and in 349 BC he superseded Chares as commander in the Olynthian War. He achieved little success, but made himself detested by his insolence and profligacy, and was in turn replaced by Chares.
After Chaeroneia the war party would have entrusted Charidemus with the command against Philip, but the peace party secured the appointment of Phocion. He was one of those whose surrender was demanded by Alexander the Great after the destruction of Thebes, but escaped with banishment. He fled to Darius III, who received him with distinction. But, having expressed his dissatisfaction with the preparations made by the king just before the battle of Issus (333 BC), he was put to death.