Xenophon of Athens was an ancient Greek philosopher, historian, soldier and mercenary, and a student of Socrates. As an historian, Xenophon is known for recording the history of his contemporary time, the late-5th and early-4th centuries BC, such as the Hellenica, about the final seven years and the aftermath of the Peloponnesian War; as such, the Hellenica is a thematic continuation of the History of the Peloponnesian War, by Thucydides.