Old Church Slavonic

Old Church Slavonic (or Old Church Slavic, and often abbreviated to OCS; словѣ́ньскъ ѩзꙑ́къ, slověnĭskŭ językŭ) was the first Slavic literary language. The 9th century Byzantine Greek missionaries Saints Cyril and Methodius are credited with standardizing the language and using it in translating the Bible and other Ancient Greek ecclesiastical texts as part of the Christianisation of the Slavic peoples. It played an important role in the history of the Slavic languages and served as a basis and model for later Church Slavonic traditions, and some Eastern Orthodox and Eastern Catholic churches use Church Slavonic as a liturgical language to this day.