 By the time the Dark Ages were underway in Greece in the 7th century BC, so was the population which exploded and carried more than half of its share of the Balkan total and over 2,000,000 people in absolute numbers.By the 5th century, the Greek archipelago contained 3,000,000 people out of 5,000,000 people in the Balkans.Alexander's campaigns opened the whole Orient to Greek settlements, an outlet for the overpopulation back home.