Around 2100 BCE the Minoan civilization on Crete was forming. The Mycenaean civilization in mainland Greece was forming around 1500 BCE. It appears that the Mycenaean’s took over the Minoans in the next couple hundred years. But somewhere around 1300 BCE there was a massive disruption of all the palaces in both locations and the Greek Dark Ages occurred. During this period writing was ‘lost’ and not rediscovered or implemented until the end of these dark ages at around 750 BCE. The larger political organizations do not seem to have existed during this period. It also appears that there was a considerable loss of population. It is still not understood what happened to cause this period of disruption in the social/political situation and no specific outside influence or climate change has been discovered.
(The Great Courses – The Origin of Civilization)