The Byzantine Emperor Justinian had a great deal of influence in shaping the policies of the Eastern Orthodox Church. He was able to play such a large role partly because as emperor.
he held both secular and religious authority as the head of the Byzantine Empire. Justinian saw himself as God's representative on Earth and believed it was his duty to maintain the unity of the Church.
One of his most notable contributions to the Eastern Orthodox Church was his codification of Roman law. He commissioned a team of legal experts to compile and systematize existing Roman laws, resulting in what is known as the Corpus Juris Civilis or the Justinian Code. This code had a profound impact on the legal systems of many European countries and influenced the development of canon law in the Eastern Orthodox Church.
Justinian also actively promoted the policies of religious unity and orthodoxy. He sought to reconcile theological differences within the Church and eliminate heretical teachings. To achieve this, he convened the Fifth Ecumenical Council in 553, known as the Second Council of Constantinople, which condemned certain theological doctrines and declared them heretical. This council played a crucial role in defining the boundaries of acceptable belief within the Eastern Orthodox Church.
Additionally, Justinian was directly involved in the appointment of Church leaders, such as patriarchs and bishops. He exerted his influence to ensure that those in positions of power would support his policies and maintain the unity of the Church.
Overall, Justinian's position as both the emperor and the head of the Eastern Orthodox Church allowed him to shape its policies significantly. He actively promoted religious unity, codified laws, and commanded the Councils, all of which greatly influenced the development and direction of the Eastern Orthodox Church.