The ancient Olympic Games took place in Olympia, in the western Peloponnese Islands. The area was considered a sanctuary and contained temples to Zeus and Hera, among other important structures. The games began there in 776 B.C. and continued until Emperor Thedosius I of Rome outlawed them in 394 A.D.
While the city-states of Greece were often in conflict with one another, the Olympic Games were held under truce so that enemies could compete against one another without fear. The ritual of holding the games every four years created the term "Olympiad" to refer to the time between the Olympics.