Orthodoxy in the West before the schism was a structurally independent group of Churches whose Patriarchate was in Rome, but whom had their own independent communities throughout Metropolitan and Archepiscopal sees in Europe, some of which were Lyons, Toledo, and Milan. Concurrent with the [[Great Schism]] in 1054, a series of events took place which ruptured the continuity of the Orthodox Church in the West with the Church in the East. The interpretation of these events (if one gets their most basic facts straight) can fall into three categories:
1) A developmental interpretation of the great schism, or the "Gradual Estrangement" theory common among Roman Catholics and Protestants, as well as a number of Orthodox convert writers, which predisposes that there were no significant changes in the 11th century that marked schism, and that those who were abandoning Orthodoxy were unaware of such, but that the nature of the divergence of belief from Orthodoxy did not become clear until much later (this view is most clearly expressed in popular literature about the history of Orthodoxy from writers such as Fr John Meyerndorff and Francis Dvornik).
2) A catastrophic interpretation of the events surrounding the great schism, or the "Ethnic Cleansing" theory proposed by a number of Orthodox writers on the West, including [[John S. Romanides|Fr. John Romanides]] and Vladimir Moss, which predisposes that heretics physically overtook the Orthodox and wiped them off the map in their native lands, or subjugated them to slavery, while replacing their liturgical forms, or that there were definitive events that ended Orthodoxy's presence in an area.