Old Church Slavonic

Medieval Slavic literary language

Old Church Slavonic (OCS) or Old Slavonic ( slə-VON-ik, slav-ON-) is the first Slavic literary language and the oldest extant written Slavonic language attested in literary sources. It belongs to the Eastern South Slavic subgroup of the South Slavic branch of the Slavic language family and is the ancestor of Church Slavonic, which remains the liturgical language of many Christian Orthodox churches. Historians credit the 9th-century Byzantine missionaries Saints Cyril and Methodius with standardizing the language and undertaking the task of translating the Gospels and necessary liturgical books into it as part of the Christianization of the Slavs.

From Wikipedia, under CC BY-SA. More on occurri.