The historian Thucydides was a citizen of Athens and lived during the most fertile period of Greek culture. His only preserved writing is his history of the Peloponnesian War, fought between Athens and Sparta and their respective allies (431-404 B.C.). This war is the decisive one in Greek history, for it sealed the doom of the independent city-states, which declined fatally in strength and importance during the following century.

For biographical details there are two kinds of sources: the evidence within Thucydides' work, by far the most reliable information, and traditions about his life and family connections that descend from research done in the Hellenistic period (323-30 B.C.), when scholars sought to reconstruct the lives of the great literary models of the classical age. This latter material exists in a life of Thucydides by Marcellinus and one shorter, anonymous biography. These works appear to be summaries...