Justinian was the last Roman Emperor to occupy the Byzantine throne. He was at the same time a Christian ruler filled with the consciousness of the Divine source of his imperial authority. His strivings towards the achievement of a universal Empire were based on Christian, as well as on Roman, conceptions. For him the ‘imperium romanum’ was to be identified with the Christian ‘oikoumene’, and the triumph of Christianity was as sacred a mission as the restoration of Roman supremacy. No ruler since Theodosius the Great hade made such an effort to convert the Empire and to root out paganism. Though numerically the pagans were not strong at this time, they still had considerable influence in learning and culture. Justinian therefore deprived them of the right to teach, and in 529 he closed the Academy of Athens, the centre of pagan neoplatonism. The scholars who were driven out found a refuge at the court of the Persian King of Kings, bringing with them the fruits of Greek learning.
In Justinian the Christian Church found a master as well as a protector, for though Christian, he remained a Roman to whom the conception of any autonomy in the religious sphere was entirely alien. Popes and Patriarchs were regarded and treated as his servants. He directed the affairs of the Church as he did those of the state, and took a personal interest in details of ecclesiastical organization. Even in matters of belief and ritual the final decision rested with him, and he summoned church councils, wrote theological treatises and composed church hymns. In the history of the relations between Church and State, the age of Justinian is the hight-watermark of imperial influence in religious matters, and no other Emperor either before or after had such unlimited authority over the Church.
--- George Ostrogorsky, History of the Byzantine State
