To be fair, the first wave of the Great Schism may be felt as early as the reign of Charlemagne - complicated, of course, by the issue of Iconoclasm (in which, however, Charlemagne himself was nearly on the heretical side) and, as so often is the case, with grave misunderstandings in language. Certainly something was seriously wrong by the time of the stormy career of Photius, let alone by the journey to Constantinople of that least diplomatic of all diplomats, Bishop Liutprand of Cremona. And conversely, in spite of the mutual excommunication of 1054, in 1092 the Eastern Emperor called to the West for help in the name of the common Christian faith - and got more of it than he ever asked, or than anyone expected. I would not say that the schism was really complete until the disastrous collapse of the Council of Florence settlement and the Orthodox canonization of Marcus of Ephesus. (Which, incidentally, also affected the Ethiopian Church, which had managed to send two representatives to the Council and accepted its conclusions!)