Christianity in Korea
Hangul, a phonemic Korean alphabet invented around 1446 by scholars in the court of Sejong the Great, was little used for several centuries because of the perceived cultural superiority of Classical Chinese (a position similar to that of Latin in Europe). However, the Catholic Church became the first Korean religious organization to officially adopt Hangul as its primary script. Bishop Siméon-François Berneux mandated that all Catholic children be taught to read it. Christian literature printed for use in Korea, including that used by the network of schools established by Christian missionaries, mostly used the Korean language and the easily learned Hangul script. This combination of factors resulted in a rise in the overall literacy rate, and enabled Christian teachings to spread beyond the elite, who mostly used Chinese. As early as the 1780s, portions of the Gospels were published in Hangul; doctrinal books such as the "Jugyo Yoji" (주교요지) appeared in the 1790s and a Catholic hymnal was printed around 1800.
Hangul
The "Hunmin Jeong-eum" states that King Sejong adapted the ("gojeon", ""Gǔ" Seal Script") in creating the Korean alphabet. The has never been identified. The primary meaning of "gǔ" is "old" ("Old Seal Script"), frustrating philologists because the Korean alphabet bears no functional similarity to Chinese "zhuànzì" seal scripts. However, Ledyard believes "gǔ" may be a pun on "Měnggǔ" "Mongol", and that is an abbreviation of "Mongol Seal Script", that is, the formal variant of the 'Phags-pa alphabet written to look like the Chinese seal script. There were 'Phags-pa manuscripts in the Korean palace library, including some in the seal-script form, and several of Sejong's ministers knew the script well.