The Panhellenic games, which pitted one Greek polis (city-state; pl. poleis) against another, were religious events and athletic competitions for talented, generally wealthy, individual athletes in the areas of speed, strength, dexterity, and endurance, according to Sarah Pomeroy in Ancient Greece: A Political, Social, and Cultural History (1999). Despite the competition between poleis in the area of arete (the Greek concept of virtue), the four, cyclical festivals temporarily united the religiously and culturally closely linked, Greek-speaking world.
These important events were held regularly during a four-year period that was named for the most famous of the four. Called an Olympiad, it was named for the Olympic games, which were held at Elis, in the Peloponnese, northwest of Sparta, for five summer days, once every four years. Peace was so essential for the purpose of convening people from throughout Greece for the Panhellenic [pan=all; Hellenic=Greek] games, that Olympia even had a famous truce for the duration of the games. The Greek term for this is ekecheiria.
Location of the Games
The Olympic Games were held at the sanctuary of the Olympian Zeus at Elis; the Pythian Games were held at Delphi; the Nemean, in Argos, at the sanctuary of Nemea, renowned for the labor in which Heracles killed the lion whose hide the hero wore from then on; and the Isthmian games, held at the Isthmus of Corinth.
These four games were stephanitic or crown games because the victors won a crown or wreath as prize. These prizes were a wreath of olive (kotinos) for the Olympic victors; laurel, for the victory most closely associated with Apollo, the one at Delphi; wild celery crowned the Nemean victors, and pine garlanded victors at the Isthmus.
"The kotinos, a crown always cut from the same old olive tree called kallistefanos (good to crown) that grew to the right of the opisthodomos of the temple of Zeus, was given as a prize to the winners of the Olympic Games, starting from the first Games held in Olympia in 776 B.C. until the last ancient Olympic Games, promoting truce and peace between peoples."
The Olive Tree as a Wreath of Glory
The Olympic games chiefly honored the Olympian Zeus; the Pythian games honored Apollo; the Nemean games honored the Nemean Zeus; and the Isthmian honored Poseidon.
Pomeroy dates the games to 582 B.C. for the ones at Delphi; 581, for the Isthmian; and 573 for the ones at Argos. Tradition dates the Olympics to 776 B.C. It is thought that we can trace all four sets of games back at least as far as the Trojan War funeral games Achilles held for his beloved Patrocles/Patroclus in The Iliad, which is attributed to Homer. Origin stories go further back than that, to the mythological period of such great heroes as Hercules (Heracles) and Theseus.
Not properly one of the panhellenic games -- and there are some noticeable differences, the Great Panathenaea was modeled on them, according to Nancy Evans, in Civic Rites: Democracy and Religion in Ancient Athens (2010). Once every four years Athens celebrated 's birthday with a 4-day festival featuring athletic competitions. On the other years, there were minor celebrations. There were team as well as individual events in the Panathenaea, with Athena's special olive oil going as the prize. There were also torch races. The highlight was a procession and the religious sacrifices.