Cyrillic script consonants from the older Glagolitic alphabet for sounds not found in Greek. Tradition holds that Cyrillic and Glagolitic were formalized either by Saints Cyril and Methodius who brought Christianity to the southern Slavs, or by their disciples. Paul Cubberley posits that although Cyril may have codified and expanded Glagolitic, it was his students in the First Bulgarian Empire under Tsar Simeon the Great that developed Cyrillic from the Greek letters in the 890s as a more suitable script for church books. Later Cyrillic spread among other Slavic peoples, as well as among non-Slavic Vlachs. Cyrillic and Glagolitic were used for
Glagolitic script the same model as "alpha" + "beta". The Slavs of Great Moravia (present-day Slovakia and Moravia), Hungary, Slovenia and Slavonia were called "Slověne" at that time, which gives rise to the name Slovenish for the alphabet. Some other, rarer, names for this alphabet are Bukvitsa (from common Slavic word "bukva" meaning "letter", and a suffix "-itsa") and Illyrian. In the Middle Ages, Glagolitsa was also known as "St. Jerome's script" due to popular mediaeval legend (created by Croatian scribes in the 13th century) ascribing its invention to St. Jerome (342–429). That claim, however, has been resolutely disproven. The epoch of