→Late Byzantine era (843-1453)
*862 Ratislav of Moravia converts to Christianity.
*863 First translations of [[Holy Scripture|Biblical]] and liturgical texts into [[Church Slavonic]] by Ss. [[Cyril and Methodius]].
*864 Prince [[Boris of Bulgaria]] is [[baptism|baptized]].
*867 Council in Constantinople held, presided over by [[Photius the Great|Photius]], which anathematizes Pope [[Nicholas I of Rome]] for his attacks on the work of Greek missionaries in Bulgaria and the use by papal missionaries of the heretical [[Filioque]]; Pope Nicholas dies before hearing the news of his excommunication; [[Basil the Macedonian]] has Emperor [[Michael III]] murdered and usurps the Imperial throne, reinstating Ignatius as patriarch of Constantinople.