Photian Schism

Timeline

1. 858Constantinople · TurkeyAfter deposing Ignatios, Michael III in 858 consecrated the scholar Photios and appointed him Patriarch of Constantinople, provoking strong objections from the Roman See over the appointment's legitimacy.
2. 863–867Constantinople · TurkeyPope Nicholas I declared Photios deposed at the Lateran Council in Rome in 863; Photios responded by convening a synod in Constantinople in 867, and the two sides excommunicated each other, severely worsening East-West relations and forming the Photian Schism. That same year Basil I deposed Photios and restored Ignatios, bringing the schism to a temporary end.