Robin Waterfield, Olympia: The Story of the Ancient Olympics
(London: Head of Zeus, 2018), page number unknown (from chapter 1):
Whether they were rich or poor, and whether they came from one of the few
great states or one of the many that were small and obscure, everyone at
Olympia recognized themselves as kin. The games were an affirmation of
Greekness that was particularly important for those visiting from overseas
or the fringes of the Greek world. When the fifth-century-BCE historian
Herodotus of Halicarnassus said that one of the things that bound all Greeks
together, wherever they lived, was their common sanctuaries and festivals,
he was thinking of the Olympic festival and others like it.5 A shared
religious festival such as the Olympics gave the Greeks a chance to
recognize their cultural unity — even though, as we shall see, it often did
little to disguise their political disunity.
Greeks lived not just in the country that is nowadays called 'Greece', but
also in separate states all over the Mediterranean and Black Sea coastlines.
From about the middle of the fifth century onwards, judges were appointed
at Olympia — they were called the Hellanodikai, the 'judges of the Greeks'
— and one of their jobs was to make sure that all contestants were genuinely
Greek, full citizens of their states (in particular, not slaves) and of good
standing in their states. Greekness remained a prerequisite for several
centuries, until from the end of the third century BCE the rule was
obsequiously bent for Romans, the new masters of the Mediterranean world
(though in fact they entered only the equestrian events, and left the rest to
5 Herodotus, Histories, 8.144