Mick, the Trojan War may have exhausted those civilizations - as recalled in the Iliad. The period that followed was kind of a “Dark Ages” of the Aegean. There are records of “Sea Peoples” who were agressive marauders who terrorized the area - pirates, basically. It took quite awhile to build up civilizations again. But certainly in the centuries leading up to the classical period there was a lot going on - Attic pottery was pretty sophisticated for example. The Greeks were busy learning how to go from tribes to city states. 😎