"from about 300 to 600, or from Constantine to Pope Gregory L, Christianity as professed by the Church, and as defined through councils, presents itself as the acknowledged faith of the Roman Empire, East and West In the subsequent two centuries, from 600 to 800, or from Gregory L to Charlemagne, the gospel is received by the Teutonic nations, over whom the sway of the Church is established. In the three centuries that follow(...)"