This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
It is a common assumption that Cyrillic, the alphabet used today for Russian, Bulgarian, Serbian and many other Slavic languages, is simply a later version of Glagolitic, the way Latin is often loosely described as descending from Greek. The real relationship is narrower and more specific. Cyrillic was created somewhat after Glagolitic, traditionally attributed to Cyril's own disciples working in Bulgaria, and it drew its letterforms mainly from Greek uncial script, the formal rounded capitals Byzantine scribes used for religious manuscripts, not from Glagolitic's own distinctive shapes. What Cyrillic did keep from Glagolitic was narrower but important: a handful of individual letters, needed to represent Slavic sounds that Greek simply had no letters for, were carried over largely intact from the older alphabet into the new one. So Cyrillic is Greek in its main structure and majority of its letterforms, with a small, functional inheritance from Glagolitic layered in for the sounds Greek could not otherwise express. Glagolitic itself did not disappear once Cyrillic became dominant; it survived for centuries as a liturgical script in parts of the Balkans, and a form of the Glagolitic liturgy is still celebrated on ceremonial occasions in a handful of Croatian Catholic communities today.