Thucydides was an Athenian historian born around 460 BCE. The son of Olorus, he possessed Thracian mining wealth and served as a general in 424 BCE during the Peloponnesian War. His failure to defend Amphipolis resulted in a twenty-year exile, which allowed him to gather information from both sides of the conflict with greater impartiality. He likely returned to Athens after 404 BCE and died sometime after 400, leaving his great work unfinished.

His sole surviving work is the History of the Peloponnesian War, an unfinished account in eight books covering the conflict from its origins to 411 BCE. Thucydides is considered the founder of scientific history, establishing a new standard for accuracy and critical evidence by rejecting myth and divine causation in favor of analyses of human nature and political power. His rigorous method and insights into political rhetoric, power dynamics, and the psychology of war have made his history a foundational text in historiography, political theory, and international relations.