The Olympic games were held to be one of the two central rituals in ancient Greece, the other being the much older religious festival, the Eleusinian Mysteries.
Areas around the Mediterranean had a long tradition of athletic events. Ancient Egyptians and Mesopotamians depicted athletic scenes in tombs of kings and their nobles. They did not, however, hold regular competitions, and those events that occurred were probably the preserve of kings and upper classes. Minoans culture held gymnastics in high esteem, with bull-leaping, tumbling, running, wrestling and boxing shown on their frescoes. The Mycenaeans adopted Minoan games and also raced chariots in religious or funerary ceremonies. Homer’s heroes participate in athletic competitions to honor the dead. In the Iliad there are chariot races, boxing, wrestling, a foot race, as well as fencing, archery, and spear throwing. The Odyssey adds to these a long jump and discus throw.
Source: Wikipedia