The Peloponnesian War

The rivalry between democratic Athens and militaristic Sparta finally erupts into open war in 431 BCE. Thucydides — an Athenian general turned historian — writes the definitive account, creating what many consider the first work of modern history. Athens suffers a devastating plague in 430 BCE that kills Pericles, launches a catastrophic failed invasion of Sicily in 415 BCE, and finally surrenders in 404 BCE. The war demonstrates how quickly a civilization at its peak can destroy itself.