Answer:
The head of the Byzantine Church was the Ecumenical Patriarch of Constantinople, who not only led the Byzantine (Greek Orthodox) Church, but all Eastern Orthodox Churches. However unlike the Pope, who usually wielded immense political and religious power capable of rivaling Kings and Emperors, the same could not be said about the Ecumenical Patriarch. More often that not, the Ecumenical Patriarch was appointed by Byzantine Emperors, making them subservient to the head of the Byzantine State. As a result one could say that the Ecumenical Patriarch technically was the head of the Byzantine Church, though his authority could be trumped by Byzantine Emperors.
Step-by-step explanation: