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.
Origin of Hangul
In order to maintain the Chinese convention of initial and final, Sejong and his ministers needed a null symbol to refer to the lack of a consonant with an initial vowel. He chose the circle, ㅇ, with the subsequent derivation of the glottal stop ㆆ "’" , by adding a vertical top stroke by analogy with the other stops, and the aspirate ㅎ "h" , parallel the account in the "Haerye." (Perhaps the reason he created a new letter rather than adopting one from ’Phags-pa was that it was awkward to write these Chinese initials in ’Phags-pa, where ㅇ and ㆆ were both written as digraphs beginning with "y," ꡭꡝ and ꡗꡖ.) However, Ledyard's explanation of the letter ㆁ "ng" differs from the "Haerye" account; he sees it as a fusion of velar ㄱ "g" and null ㅇ, reflecting its variable pronunciation. The Korean alphabet was designed not just to write Korean, but to accurately represent Chinese. Many Chinese words historically began with , but by Sejong's day this had been lost in many regions of China, and was silent when these words were borrowed into Korean, so that only remained at the middle and end of Korean words. The expected shape of a velar nasal, the short vertical stroke (⃓) that would be left by removing the top stroke of ㄱ "g", had the additional problem that it would have looked almost identical to the vowel ㅣ "i" . Sejong's solution solved both problems: The vertical stroke left from ㄱ "g" was added to the null symbol ㅇ to create ㆁ "ng", iconically capturing both regional pronunciations as well as being easily legible. Eventually the graphic distinction between the two silent initials ㅇ and ㆁ was lost, as they never contrasted in Korean words.