The '''Cyrillic alphabet''' is a set of letters that are used for certain [[Slavic language]]s, principally [[Russian]]. Based on [[Greek]] letters, it has a longer [[alphabet]] than do the Roman or Greek alphabet, to better accommodate the different phonemes encountered in Slavic languages. They are named for [[Saint Cyril]], who, with his brother [[Saint Methodius]], were apostles to the Slavs, much as [[Saint Patrick]] was apostle to the [[Celts]]. Cyril is usually credited for devising [[Glagolithic]] letters (for [[Croatian]]), but the attribution to him for Cyrillic letters is less firm.
The Old Church Slavonic (OCS) version of the [[Bible]] is close to what the historical linguists term proto-Slavic, but is actually a very old form of Bulgarian/Proto-South-Slavic. Cyrillic letters are used for this version of Scripture.