Which of the following statements about the idea of combining secular government with religious authority in both the Roman and Byzantine empires is true? The pope eventually became the only ruler with power in the Byzantine Empire. Unlike the Roman era, in the era of Constantine the Great the patriarch and the emperor ruled jointly. Constantine's efforts to rule in church affairs within the Byzantine Empire marked a change in the relationship between the church and government. The pope was a political force in the late Roman Empire, but not in the early Byzantine Empire.