Photian Schism

Timeline

1. 858Constantinople · ByzantinePhotios succeeded to the patriarchate of Constantinople after Patriarch Ignatios was deposed; the procedures of his appointment and the handling of his predecessor raised questions in Rome, and disputes over East–West ecclesiastical jurisdiction first emerged.
2. 863Rome · RomePope Nicholas I convened a synod in Rome, excommunicated Patriarch Photios and denied his patriarchal status, while issuing condemnations to the East over missionary rights in Bulgaria and the filioque doctrinal dispute; the Eastern and Western churches openly broke with each other.