U+2C20 Glagolitic Capital Letter Yeri

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The Glagolitic script ( GLAG-ə-LIT-ik, ⰳⰾⰰⰳⱁⰾⰻⱌⰰ, glagolitsa) is the oldest known Slavic alphabet. It is generally agreed that it was created in the 9th century for the purpose of translating liturgical texts into Old Church Slavonic by Saint Cyril, a monk from Thessalonica. He and his brother Saint Methodius were sent by the Byzantine Emperor Michael III in 863 to Great Moravia to spread Christianity there. After the deaths of Cyril and Methodius, their disciples were expelled and they moved to the First Bulgarian Empire instead. The Early Cyrillic alphabet, which developed gradually in the Preslav Literary School by Greek alphabet scribes who incorporated some Glagolitic letters, gradually replaced Glagolitic in that region. Glagolitic remained in use alongside Latin in the Kingdom of Croatia and alongside Cyrillic until the 14th century in the Second Bulgarian Empire and the Serbian Empire, and later mainly for cryptographic purposes.

Glagolitic also spread to the Kievan Rus' and the Kingdom of Bohemia, though its use declined there in the 12th century, although some manuscripts in the territory of the former retained Glagolitic inclusions for centuries. It had also spread to Duklja and Zachlumia, from which it reached the March of Verona where the Investiture Controversy afforded it refuge from the opposition of Latin rite prelates, and allowed it to entrench itself in Istria, spreading from there to nearby lands.

It survived there and as far south as Dalmatia without interruption into the 20th century for Church Slavonic in addition to its use as a secular script in parts of its range, which at times extended into Bosnia, Slavonia, and Carniola, in addition to 14th-15th century exclaves in Prague and Kraków, and a 16th-century exclave in Putna.

Its authorship by Cyril was forgotten, having been replaced with an attribution to St. Jerome by the early Benedictine adopters of Istria in a bid to secure the approval of the papacy. The bid was ultimately successful, though sporadic restrictions and repressions from individual bishops continued even after its official recognition by Pope Innocent IV. These had little effect on the vitality of the script, which evolved from its original Rounded Glagolitic form into an Angular Glagolitic form, in addition to a cursive form developed for notary purposes.

But the Ottoman conquests left the script without most of its continental population, and as a result of the Counter-Reformation its use was restricted in Istria and the Diocese of Zagreb, and the only active printing press with a Glagolitic type was confiscated, leading to a shift towards Latinic and Cyrillic literacy when coupled with the Tridentine requirement that priests be educated at seminaries. The result was its gradual death as a written script in most of its continental range, but also the unusually late survival of medieval scribal tradition for the reproduction of Glagolitic texts in isolated areas like the island of Krk and the Zadar Archipelago. Although the Propaganda Fide would eventually resume printing Glagolitic books, very few titles were published, so the majority of Glagolitic literary works continued to be written and copied by hand well into the 18th century.^: 9 Of the major European scripts, only the Arabic script is comparable in this regard.

In the early 19th century, the policies of the First French Empire and Austrian Empire left the script without legal status and its last remaining centers of education were abolished, concurrent with the weakening of the script in the few remaining seminaries that used the cursive form in instruction, resulting in a rapid decline. But when the Slavicists discovered the script and established it as the original script devised by Cyril, Glagolitic gained new niche applications in certain intellectual circles, while a small number of priests fought to keep its liturgical use alive, encountering difficulties but eventually succeeding to the point that its area expanded in the early 20th century.

Latinic translations and transliterations of the matter of the missal in this period led to its decline in the decades before Vatican II, whose promulgation of the vernacular had the effect of confining regular use of Glagolitic to a few monasteries and academic institutions, in addition to a small population of enthusiasts, whose numbers grew and shrank with the prevalence of the script in literature, but grew exponentially in pious and nationalist circles in the years leading up to and following Independence of Croatia, and again more broadly with the Internet.