The Great Schism and its two paradoxes
In order to obtain full authority in Italy, Leon IX would subordinate the Byzantine episcopal chairs in southern Italy, already taken out of the authority of Constantinople by the Normans, to the Church of Rome. As a result of his alignment policy in the West, in the early 1053, he made all Byzantine churches in Italy to comply with Latin practices, as well as the new discipline rules he had imposed, under the threat of abolition. As a response to the pope’s gesture, perceived as offensive by patriarch Mihail Cerularia, all Latin churches in Constantinople were forced to join the Byzantine practices in the same year under the sanction of definitive closure. These things abundantly fueled the suspicions that led to the schism.
MIRCEA CRISTIAN PRICOP