Little is known about Thucydides. The available information about him comes from his few references to himself in The History of the Peloponnesian War. His writing suggests that he was educated as an upper-class Athenian. He must have been more than 30 years old in 424 BCE, when he was elected Strategos (general), as that was a requirement of that office. This makes 454 BCE the latest possible date for his birth; most scholars suggest 460 BCE as his birth year. As a general, he was not a success; he failed in his mission and was exiled from Athens for 20 years. He addresses this as follows: “By reason of my exile, I had leisure to observe affairs somewhat particularly” (5.26.5).

Thucydides notes that he wanted to write the story of this war but intended to do so differently than had been previously attempted. In his era, the writing of history, a word derived from the ancient Greek term for inquiry, was slowly taking shape as an intellectual and analytical enterprise, rather than a poetic one, as in the case of Homer’s epics. Other writers, such as Herodotus, also attempted to document historical events, but they relied on the gods for things they could not explain.