It is said that three months before an Olympiad, the king of Elis proclaimed that a "holy truce" in all of Greece to encourage participation in the games. In ancient Greece, many city states existed within the single Hellenistic cultural sphere. The spirit of harmony and peace that underlay the ancient Olympics meant that even battles between city states were halted in favor of sports competitions at least once every four years, and this was in an age of almost constant warring.
The Olympics were so sacred and inviolable that thousands of spectators watched the final boxing bouts at the Olympian stadium even when the country's survival itself was endangered by the Persian invasion in 480 B.C.