The end of Pericles’ long and useful life was troubled by a new war between Athens and Sparta; for, as soon as the thirty-years’ truce was ended, both cities flew to arms. The war which then began, and which in history is known as the Peloponnesian War, lasted almost as long as the truce; that is to say, for nearly thirty years.

Pericles knew very well that the Athenians, not being so well trained, were no match for the Spartans on land. He therefore advised all the people to come into the city, and take refuge behind the mighty walls, while the fleet carried on the war by sea.