Slavic Languages, subfamily of the Indo-European family of languages (see Indo-European Languages). Today the Slavic languages are spoken by more than 250 million people in eastern and central Europe, in most of the Balkan Peninsula, and in northern Asia. The Slavic languages share certain important traits with the Baltic languages, and some scholars place both language groups into a Balto-Slavic subfamily. The modern Slavic languages are divided into three branches:

East Slavic: Russian, or Great Russian; Ukrainian, also Little Russian or Ruthenian; and Belarusian or White Russian

South Slavic: eastern group—Bulgarian and Macedonian; western group—Bosnian, Croatian, Serbian, and Slovenian

West Slavic: Czech-Slovak group—Czech, Slovak, and other dialects, such as Bohemian and Moravian; Lekhitic group—Polish and the various Kashubian dialects (remnants of an older Pomeranian language); Sorbian or Lusatian group—High and Low Sorbian (Wendish)

Some modern Slavic languages (Czech, Slovak, Slovenian, and Polish) are written in the Latin alphabet, and their speakers are predominantly Roman Catholic. Other Slavic languages (Russian, Ukrainian, Belarusian, Macedonian, and Bulgarian) use variations of the Cyrillic alphabet as a result of the influence of the Eastern Orthodox church. Serbian is primarily written in the Cyrillic alphabet and Bosnian and Croatian in the Latin alphabet (see Bosnian, Croatian, and Serbian Languages). The invention of the Cyrillic alphabet, an adaptation of the Greek alphabet, is attributed traditionally to Saint Cyril, a Greek missionary. It is related to the Glagolithic alphabet created by Sts. Cyril and Methodius to translate the New Testament into the language of the Slavic peoples who, by the 9th century, had begun to embrace Christianity. The language written in this alphabet is known as Old Slavonic or Old Church Slavonic and is used as a liturgical language. For most of the middle ages Old Slavonic was the language of the ecclesiastical literature and of official and diplomatic documents.

For more information, see separate articles on many of the languages mentioned. See Slavic Peoples; Wends.