In Greek tradition the Olympic Games began with the victory of Coroebus in a foot race in 776 B.C. This date is critical regardless of its historical accuracy because of the later Greek custom of dating subsequent events from it. Such a practice was a major advance in chronological bookkeeping since more Greek cities did not number their years in numerical sequence but preferred to distinguish individual years by reference to the name of a public official or high priest then reigning. Obviously this system could not correlate events in different cities. Such reckoning had to await the adoption of an internationally significant event as a fixed point in time from which all cities could date their history.
The year 776 B.C. probably marked the start of the international character of the Olympic Games rather than their inception, since before that time they were held as a local event for those living in the immediate vicinity of Olympia in the northwest corner of the Peloponnesus. The twenty-third book of the Iliad, recording the athletic games staged by Achilles in honor of his dead companion Patroclus, may suggest the way in which the Olympic Games probably evolved as a regular commemoration of the death of Pelops, the local hero and deity of the region around Olympia. However, the development of this purely local rite into a religious festival in honor of the father of the gods, Zeus, is untraceable. The dedication to Zeus nevertheless bestowed an international character on the contests, signalized by the first formal interstate competition in 776 B.C.
Apparently in its early years the agenda of the festival included only competition in foot racing and wrestling. From the list of Olympic victors kept by ancient historians it seems that Sparta dominated the games in the eighth century. Reorganization in the seventh century involving the addition of chariot racing and single-horse feats, together with the subsequent Spartan withdrawal from competition, indicate that control of the games had passed into new hands, possibly those of Pheidon, the energetic tyrant of Argos and a vigorous opponent of Spartan domination in the Peloponnesus. The fame of the expanded games attracted competitors from as far away as Sicily and southern Italy.
In 472 B.C., the program was further expanded. The length of time set aside for the games was extended to five days, the first being devoted to religious aspects of the festival: the formal sacrifices, and the solemn oath of contestants and judges to act fairly. The next day featured chariot and horse races, and the pentathlon (running, jumping, javelin and discus throwing, and wrestling). After contests for young boys on the third day, the program returned on the fourth day to men's competition in boxing, wrestling, running, jumping, and in a final race for men clad in full armor. The festival ended on the fifth day with sacrifices in the morning and a final banquet for the victors, who received wreaths of wild olive leaves as symbols of their success.
The site of Olympia itself was situated in a small but splendid valley between low hills flanking the River Alpheus. These physical endowments were enhanced by lavish architecture. The older temples, gradually eclipsed by new construction, gave way eventually to the magnificent temple of Zeus completed in 457 B.C. Competition in the games was open to all who spoke the Greek language, so that contestants and spectators came from all parts of the ancient world. To facilitate this traffic, a period of general truce was proclaimed guaranteeing all travelers safe passage, a development of no small import in the refinement of interstate relationships.
The Olympic Games eventually provided a natural political forum for the expression of new ideas. In 426 B.C., during the bitter war between Athens and Sparta, the orator Gorgias, for example, appeared at the Olympic Games to urge the end of such fratricidal conflicts and the undertaking of a united Greek expedition against the Persian empire. Presentation of the idea of a politically united Greece seemed appropriate in the setting of the Olympic Games, themselves a living expression of religious unity. Although the example of the games failed to induce the Greeks to overcome the divisive aspects of their political life, the Olympic Games continued to be celebrated as an expression of cultural and religious unity until their abolition by the Roman emperor Theodosius in A.D. 393.
The Olympic Games also served as a model for other festivals. In 582 B.C., the Pythian Games in honor of Apollo were inaugurated at Delphi; in 581 B.C., the Isthmian Games were established at Corinth in honor of Poseidon; finally, in 573 B.C. at Nemea, a city north of Argos, the first Nemean Games were held. None of these later imitations of the Olympic Games, however, acquired the renown or international importance as those first widely celebrated for Zeus in 776 B.C.