Excerpts from Books and Wikipedia
"In the 8th century BC, Greece began to emerge from the Dark Ages which followed the fall of the Mycenaean civilization. Literacy had been lost and Mycenaean script forgotten, but the Greeks adopted the Phoenician alphabet, modifying it to create the Greek alphabet. Objects with Phoenician writing on them may have been available in Greece from the 9th century BC, but the earliest evidence of Greek writing comes from graffiti on Greek pottery from the mid-8th century. Greece was divided into many small self-governing communities, a pattern largely dictated by Greek geography: every island, valley and plain is cut off from its neighbors by the sea or mountain ranges." [Wikipedia]
"Sometime around 800 BC—a very vague and general estimate—this growing sense of a single cultural identity led to the weaving together of a number of different historical traditions (many of them Mycenaean) into two related epic poems which would soon be claimed by the entire peninsula as the heritage of every city on it: the Iliad and the Odyssey." [Bauer: Ancient World, p. 351]
"These sacred sites were rapidly becoming “pan-Hellenic . . . " [Bauer: Ancient World, p. 555-7]