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
St. Cyril Peak St. Cyril Peak St. Cyril Peak (Vrah Sv. Kiril \'vr&h sve-'ti 'ki-ril\) rises to 1,505m in Friesland Ridge in Tangra Mountains on Livingston Island in the South Shetland Islands, Antarctica. The peak is linked to St. Methodius Peak to the southwest by Vladaya Saddle and surmounts Ruen Icefall to the west, Macy Glacier to the east and Prespa Glacier to the south. The peak is "named after St. Cyril (827-869 AD) who, together with St. Methodius, created the Glagolitic alphabet and translated the Holy Books into Bulgarian language". The peak is located at , which is 4.15 km south-southwest of