In 1054, relations between the Eastern and Western traditions within the Christian Church reached a terminal crisis, known as the East–West Schism. Although there was a formal declaration of institutional separation, on July 16, when three papal legates entered the Hagia Sophia during Divine Liturgy on a Saturday afternoon and placed a bull of excommunication on the altar, the so-called Great Schism was actually the culmination of centuries of gradual separation.