Numerous Cyrillic alphabets are based on the Cyrillic script. The early Cyrillic alphabet was developed in the First Bulgarian Empire during the 9th century AD (in all probability in Ravna Monastery) at the Preslav Literary School by Saint Clement of Ohrid and Saint Naum and replaced the earlier Glagolitic script developed by the Byzantine theologians Cyril and Methodius (in all probability in Polychron). It is the basis of alphabets used in various languages, past and present, in parts of Southeastern Europe and Northern Eurasia, especially those of Slavic origin, and non-Slavic languages influenced by Russian. As of 2011, around 252 million people in Eurasia use it as the official alphabet for their national languages. About half of them are in Russia. Cyrillic is one of the most-used wr