ON OCTOBER 9th South Koreans celebrate the 567th birthday of Hangul, the country's native writing system, with a day off work. South Korea is one of the few countries in the world to celebrate its writing system. The public holiday, originally introduced in 1945, was reintroduced this year after being discontinued in 1991 at the request of employers. The day commemorates the introduction of the new script in the mid-15th century, making Hangul one of the youngest alphabets in the world. It is unusual for at least two more reasons: rather than evolving from pictographs or imitating other writing systems, the Korean script was invented from scratch for the Korean language. And although Hangul's elements are phonemic like the letters in an alphabet, they are grouped into characters representing a whole syllable, which is why it is often called a "syllabary" rather than an alphabet. How was Hangul created? Before 1446, Koreans had no writing system of their own. The educated elite wrote in hanja, classical Chinese characters, to record the meaning—but not the sound—of Korean speech. The Chinese script, however, was poorly suited to languages with complex grammars like Korean; though a leading scholar of the 7th century formalised Korea’s Idu script, a mixture of hanja and special grammatical markers, including new characters for Korean names, only the privileged few with a Confucian education could understand it. In 1443 King Sejong noted that using Chinese characters for Korean was “like trying to fit a square handle into a round hole”. He disliked the fact that so few of his subjects could express their concerns to him. “Saddened by this”, he proclaimed, “I have developed 28 new letters. It is my wish that people may learn these letters easily and that they be convenient for daily use”.

Initially known as Hunmin Jeongeum (or "proper sounds for instructing the people"), the script was proclaimed as the first Korean alphabet in 1446—though its muted reception, especially within Korea’s aristocratic class, meant it was relegated to women’s diaries and children’s storybooks for centuries. It was revived under Japanese influence in the late 19th century as a means of weakening China's hold on the peninsula—only to be banned again in favour of the Japanese language. Its origins are disputed. Koreans celebrate King Sejong as its creator: one account says he almost lost his eyesight working on the alphabet. He appears in historical records as a scholarly king who wrote poetry (and is also credited with inventing a sundial and a rain gauge, among other things). But some scholars doubt he created Hangul single-handedly. It is more likely, they say, that linguists in the Hall of Worthies, a royal academy he set up, were its masterminds. Its letters are composed of a combination of lines and circles only, combined to form 12,000-odd phonemes. Its three main vowels (ㆍ, ㅡ, ㅣ) represent the sky, the earth and man. The shape of its consonants is derived from that of the mouth, lips and tongue in forming their sounds, so that a ㄱ is the shape of the tongue as it forms a ‘g’ sound (add a line, like so ㅋ, for an aspirated ‘g’, and double the letter , ㄲ, for one with a glottal stop). This makes Hangul one of just a handful of so-called featural alphabets, including Pitman Shorthand, the Shavian alphabet and Tengwar, one of Tolkien’s fictional writing systems. For Hangul exceptionalists, all this points to the script’s uniqueness; others suggest that the shapes of five Hangul letters came from the Mongol ‘Phags-pa script, designed by a Tibetan monk in the 13th century as a universal language for the empire.

The script has since evolved. Its syllabic blocks were first penned in vertical columns, but are now written from left to right, with Western spacing and punctuation. Four characters have become obsolete, so that just 24 are now used. But their simplicity—King Sejong assured his people that "a wise man can acquaint himself with them before the morning is over; a stupid man can learn them in the space of ten days”—is widely thought to have contributed to Korea’s exceptionally high literacy rate, in both North and South (where it is close to 100%). Advances in computing, some say, may also have been boosted by the ease with which Hangul can be entered into PCs and phones. Perhaps most surprisingly of all, it is not just used to write Korean. The Cia-Cia, an ethnic minority in Indonesia, has adopted Hangul to record its Malayo-Polynesian language, which lacks an indigenous writing system of its own.