Thucydides (c. 460 – c. 400 BCE) was an Athenian historian and general known for his work, the History of the Peloponnesian War, which details the conflict between Sparta and Athens from its inception in 431 BCE until 411 BCE. He is recognized for his methodical approach to history, emphasizing impartiality and evidence-based analysis, and for excluding divine intervention from his narratives. This has led to his designation as the father of 'scientific history' and the school of political realism, which interprets political behavior through the lenses of fear and self-interest.Thucydides identified himself as an Athenian from the deme of Halimous, son of Olorus. He participated in the Peloponnesian War, contracted the plague, and was exiled due to his failure to prevent the fall of Amphipolis to the Spartans in 422 BCE. His military command in the region was significant, as he was sent to Thasos in 424 BCE. During the Battle of Amphipolis, he was unable to reach the city in time to assist its defense, leading to its capture and his subsequent exile for twenty years. This period allowed him to observe the war from both Athenian and Peloponnesian perspectives, which he later incorporated into his historical account.Thucydides began writing his history at the war's outbreak, believing it to be a significant conflict worthy of documentation. His narrative, which breaks off in 411 BCE, reflects his firsthand experiences and extensive research, including interviews and written records. He is noted for his inclusion of formal speeches, which he reconstructed rather than quoted verbatim, to convey the essence of the discussions that took place during the war.Thucydides's work has had a lasting impact on historiography, influencing both Hellenistic and Roman historians. His style is characterized by a focus on political events, with little emphasis on cultural or social aspects. He viewed history as a record of political life, devoid of moral judgments, and his writings have been regarded as foundational for modern historical methodology.Later sources provide limited information about Thucydides's life, with some accounts suggesting he returned to Athens after the war's conclusion in 404 BCE, only to be murdered on his way back. However, many scholars believe he lived until at least 397 BCE. His narrative ends abruptly, leading to speculation about the circumstances of his death. Thucydides's analysis of human nature, particularly in the context of war and suffering, remains a critical aspect of his historical perspective.Thucydides's History of the Peloponnesian War is divided into eight books, a classification likely established by later scholars. His work is distinguished from that of his predecessor, Herodotus, in its rigorous approach to factual reporting and its exclusion of moral lessons. Thucydides's influence extends into modern political thought, particularly in discussions of realism and the nature of power in international relations.