Xenophon of Athens (c. 431 BC - 354 BC) was an ancient Greek philosopher, historian, soldier, mercenary, and student of Socrates. Xenophon's works span several genres and are written in plain-language Attic Greek, for which reason they serve as translation exercises for contemporary students of the Ancient Greek language. As a historian, Xenophon is known for recording the history of his time, the late-5th and early-4th centuries BC, in such works as the Hellenica, which covered the final seven years and the aftermath of the Peloponnesian War (431-404 BC), thus representing a thematic continuation of Thucydides' History of the Peloponnesian War.