The Pentecontaetia

The Pentecontaetia (Pentekontætia, πεντηκονταετία) or “the account of the fifty years” is a term first used by Thucydides to describe, in Book 1, Sections 89 to 117 (1.89-117) of his History of the Peloponnesian War, the period between the Battle of Plataea in 479 BCE to the start of the Peloponnesian War in 432 BCE. The historian sought to describe how the Athenians “had become so powerful” (1.89.1) and to highlight those key events he believed most alarmed the Spartans and led to the Peloponnesian War. The period is widely considered as the “Golden Age of Athens” when many of ancient Greece's greatest works were produced in architecture, engineering, the arts, history, astronomy, and philosophy.