Thucydides

Thucydides was a historiographer and army general. During the Peloponnesian War against Sparta, he was a commander in the Athenian army. In 424, he was banished from Athens for losing the battle of Amphipolis and began describing the course of the war, basing himself on his own experiences and on eye-witness accounts, in his main work: the History of the Peloponnesian War. Due to his systematic approach, he is often referred to as the founding father of the scientific method in historiography.