The Early Cyrillic alphabet, also called classical Cyrillic or paleo-Cyrillic, is an alphabetic writing system that was developed in Medieval Bulgaria in the Preslav Literary School during the late 9th century. It is used to write the Church Slavonic language, and was historically used for its ancestor, Old Church Slavonic. It was also used for other languages, but between the 18th and 20th centuries was mostly replaced by the modern Cyrillic script, which is used for some Slavic languages, and for East European and Asian languages that have experienced a great amount of Russian cultural influence.

The Preslav Literary School, also known as the '''Pliska Literary School''' or '''Pliska-Preslav Literary school''' was the first literary school in the medieval First Bulgarian Empire. It was established by Boris I in 886 in Bulgaria's capital, Pliska. In 893, Simeon I moved the seat of the school from the First Bulgarian capital Pliska to the new capital, Veliki Preslav. Preslav was captured and burnt by the Byzantine Emperor John I Tzimisces in 972 in the aftermath of Sviatoslav's invasion of Bulgaria.