Old Church Slavonic or Old Slavonic, also known as Old Church Slavic or Old Slavic, was the first Slavic literary language (autonym словѣ́ньскъ ѩꙁꙑ́къ, slověnĭskŭ językŭ). It is also referred to as Paleo-Slavic (Paleoslavic) or Palaeo-Slavic (Palaeoslavic), not to be confused with the Proto-Slavic. It is often abbreviated to OCS. The 9th-century Byzantine missionaries Saints Cyril and Methodius are credited with standardizing the language and using it in translating the Bible and other Ancient G