CLEON (d. 422 B.C.), Athenian politician during the Pelo ponnesian War, was the son of Cleaenetus, from whom he in herited a tannery. He was the first prominent representative of the commercial class in Athenian politics. He came into notice first as an opponent of Pericles, and in his opposition somewhat curiously found himself acting in concert with the aristocrats, who equally hated and feared Pericles. In 43o, when the city was devastated by the plague, Cleon headed the opposition to the Periclean regime. Pericles was accused of maladministration of public money, with the result that he was actually found guilty though he was re-elected in 429. The death of Pericles (429) left the field clear for Cleon. Hitherto he had only been a vigorous opposition speaker, a critic and accuser of state officials. He now came forward as the champion and leader of the democracy, and was for some years undoubtedly the foremost man in Athens. He was gifted with natural eloquence and a powerful voice, and knew how to work upon the feelings of the people. He be came the leader of the war party in opposition to Nicias and the moderates, who favoured a cautious strategy and an early peace.
In 427 when Mytilene, which had revolted, fell, Cleon pro posed that all its citizens should be put to death, and the women and children enslaved. His policy was to hold down the empire, now a "tyranny," by naked force. His decree was passed, but rescinded next day, in time to save Mytilene.
In 425 he, when the Spartans were blockaded in Sphacteria, brought about the rejection of the terms offered by Sparta, and in the hope of securing a peace which should restore Atnens' land empire. He then reached the summit of his fame by capturing the Spartans on the island (see PYLos). Much of the credit of this success, the most notable which the Athenians won during the Archidamian War, was due to the military skill of his colleague Demosthenes; but it was due to Cleon's determination that the Ecclesia sent out the additional force which was needed. About this time Cleon doubled the tribute of the allies (see DELIAN LEAGUE) and raised the pay of the Athenian jurors from two to three obols (Schol. Ar. Wasps 88). In 422, after the close of the armistice, Cleon, who was eager to continue the war, went to recover Thrace from Brasidas, but, after capturing several cities, was taken by surprise at Amphipolis, defeated and killed. With his death, the peace party at Athens gained power, and the Peace of Nicias was concluded. (See PELOPONNESIAN WAR). Cleon is represented by Aristophanes and Thucydides in an extremely unfavourable light. But neither can be considered an unprejudiced witness. Aristophanes was not only opposed to Cleon's political programme, but bore him a personal grudge, having been prosecuted by the demagogue after the production of his Babylonians. Moreover, his treatment of Socrates should put us on our guard against accepting his evidence against Cleon. Thucydides had been exiled by a decree proposed by Cleon after the loss of Amphipolis.