The Cyrillic script is an alphabetic writing system employed across Eastern Europe and north and central Asia. It is based on the Early Cyrillic, which was developed during the First Bulgarian Empire in the 9th century AD at the Preslav Literary School. 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. , around 252 million people in Eurasia use it as the official alphabet for their national languages, with Russia accounting for about half of them. Cyrillic is one of the most used writing systems in the world.