The Olympic Games were a series of athletic competitions held for representatives of various city-states of Ancient Greece held in honor of Zeus. The exact origins of the Games are shrouded in myth and legend but records indicate that they began in 776 BC in Olympia in Greece. They were celebrated until 393 AD when they were suppressed by Theodosius I as part of the campaign to impose Christianity as a state religion. The Games were usually held every four years, or olympiad, as the unit of time came to be known. During a celebration of the Games, an Olympic Truce was enacted so that athletes could travel from their countries to the Games in safety. The prizes for the victors were olive wreaths or crowns.