Query: What event is believed to be the ethnic basis of the Greeks society?
Context: The ethnogenesis of the Greek nation is linked to the development of Pan-Hellenism in the 8th century BC. According to some scholars, the foundational event was the Olympic Games in 776 BC, when the idea of a common Hellenism among the Greek tribes was first translated into a shared cultural experience and Hellenism was primarily a matter of common culture.