Hippias of Athens (Greek: Ἱππίας ὁ Ἀθηναῖος) lived in Athens in the 6th century BC. He was one of the sons of Peisistratus, the ruler of Athens. Hippias succeeded Peisistratus in 527 BC. and became tyrant of Athens.
His brother Cleisthenes was murdered in 514 BC. Hippias' behavior changed. He became cruel and angry, executing people in revenge, and taking away the freedom of people. He also was afraid of threats from the aristocrats. In the end his uncle Cleisthenes decided to overthrow Hippias and gain power for himself and his family. Hippias was captured and sent into exile, away from Athens forever in 510 BC.
Hippias fled to Persia, and the Persians threatened to attack Athens if they did not accept Hippias. The Athenians preferred to remain democratic despite the danger from Persia. Soon after, the Ionian Revolt against Persian rule began in the Greek colonies in Asia Minor. It was put down in 494 BC, but Darius I of Persia was keen to punish Athens for its role in the revolt. In 490 BC Hippias, still in the service of the Persians, led Darius to Marathon, in Greece. The Battle of Marathon began a series of Greek victories which made Athens and its colonies successful. The next 200 years saw flowering of the classical Greek civilisation.