The Early Byzantine Empire was much greater than that of the Middle or Late Empires not only in size and political power but also in regard to social achievement. In other words, although Byzantine society in many respects followed in the footsteps of the previous societies, it provided breakthroughs that endured throughout the course of Byzantium. It merged Christianity with the Greco-Roman tradition, established Christian dogma and provided the social foundations for Christian life. It also created intellectual concepts such as Christian literature and art and introduced a social system that was based on legal conditions dictated by a central, or imperial, power rather than on free trade and private contract. Indeed it is difficult to find an institution or concept that did not emerge during this early period.