|The sacred truce
A few months before the start of the games, ambassadors left Olympia, Delphi, Isthmia or Nemea and visited all corners of the Greek world. In every city they declared a sacred truce. Some supporters of the modern Olympic movement think very highly of this truce. In 1956, when the games were nearly cancelled because of the Cold War, I.O.C.-president Avery Brundage said: “In the Golden Age there was an Olympic truce and all warfare stopped during the period of the games, [but now] after two thousand years of civilization, we stop the games and continue our wars.”
It is true that the ancient Olympic games were held during the Persian and the Peloponnesian wars, while the modern Olympics were cancelled during the First and Second World War, but that can be explained by the scale of the wars, not by the Olympic truce. The sacred truce did not put a stop to all warfare, only conflicts which hindered the games. The truce protected travellers on their way to the sanctuary and only forbade military operations against and by the organizing city.
A few times the ancient truce was broken. In 420 BC, the Spartans were excluded from the Olympic games because they had attacked a part of the Elean territory. In 364 BC, Arcadian soldiers even attacked the holy domain of Olympia during the games.