To be allowed to take part in Greek games, an athlete had to be 'Greek', i.e. 'citizen of a Greek city'. What constituted the Greek world changed, however, throughout the history of the games. In the classical period, there were Greek cities in mainland Greece and on the Aegean islands, along the coast of Asia Minor (present-day Turkey), in Southern Italy and Sicily and in Cyrenaica (the north-east of present-day Libya).

With the conquests of Alexander the Great in the late fourth century BC, the Greek world expanded enormously: all of Asia Minor and the rest of the Middle-East until Afghanistan was added, with important centres in present-day Lebanon and Egypt. In all these regions new Greek cities were founded, which sent out athletes and organized games. In the second century BC, Rome became a 'Greek city' and Roman citizens were allowed to participate in the Greek games as well.

In the imperial period, the whole Greek world formed part of the Roman empire. In the second and third centuries AD, the growing 'autochthonous' provincial towns received equal status to Greek and Roman cities. They celebrated this new status with the introduction of new Greek games. This even happened present-day Tunisia, where beautiful mosaics document these games. This is remarkable, since Greek games did not exist in the West, except in Italy itself.

On this map one can see the evolution of the Greek world. The Greek world about the fifth century BC is indicated in red, in the third century BC in yellow and in the third century AD in green.