Theopompus of Chios lived from appr. 378 BC until appr.320 BC. The precise date of his death is unknown. Theopompus is a Greek historian and one of the representatives of the rhetorical history. In his youth theopompus lived together with his father, Damasistratus, in Athens. They had been exiled from their native island chios due to sympathies with the spartian faction on the island of Chios. In Athens he met Isocrates, and became his pupil. He made great fame in rhetoric history. Rhetoric can be described as the way to convince a person about a certain subject or matter. In other words "the art of persuasion through language". Rhetoric is known as the opposite of dialectic. According to Aristotle dialectic is the way to find the truth, rhetoric is the method required to communicate the truth. Being a student of Isocrates, it is belived that theopompus was active as an speaker for some time. It is said that Isocrates was poor in his speech. Theopompus once delivered a Olympian speech. Probably he made other speeches at several festivals too.

When Alexander the great came to power theopompus was able to return to Chios. In Chios he was the leader of the aristocratic party. After Alexander the Great died he was again exiled from Chios and he traveled to the city Ptolemy in Egypt.

His works has not survived in original form. Theopompus has been quoted be many historians after him. Nowadays 370 fragments has been identified as his works. Theopompus his works are amongst other the Philippika ("History of king Philip") and the Hellenika ("Greek history"). The philippika is a work of totally 58 books was finished in 324 and speaks about the reign of the Macedonian king Phillip. The hellenika describes the Peloponnesian war from the 411 BC until 394 BC. From the original 12 books only 19 fragments remain today.

Theopompus also traveled a lot. He knew many of the person he wrote about personally. We know that in his age he was blamed of being prejudice in his writings. Through the remaining fragments it appears he was fairly objective. For instance he stayed at the kingdom of king Phillip when he wrote the philippika but he criticizes king Phillip for it alcoholism and immorality.