Numerous alphabets are based on the Cyrillic script. The Early Cyrillic script 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. 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 writing systems in the world.