Byzantine era, was not at all a time of decline. It was the continuation of the states, heritage of Alexander the Great, with Roman ecumenical spirit and Greek-Orthodox christian ethics. Κοινή Αττική Greek as language of the State and common people and Greek philosophy, containing mostly or populations within its borders. Byzantine era is Ancient Greece with Modern Greece in an unbroken line of thousands years of historical that produced the greatest civilizations the world has ever know, brought the and born the modern western culture. 
