Who Invented Hangul? King Sejong and the Story of 훈민정음

King Sejong (세종, Sejong), the fourth king of the Joseon dynasty, invented Hangul. He finished it in 1443 and published it in 1446 under the name 훈민정음 (Hunminjeongeum), “the correct sounds for teaching the people”, because ordinary Koreans had no practical way to write their own language.

Most writing systems grew slowly over centuries and nobody knows who started them. Hangul is one of the rare scripts with a known author, a known date and a book that explains its design. That book is why we know so much about it today.

The problem: Korean written in Chinese characters

Before 1443, educated Koreans wrote in Classical Chinese, using Chinese characters called 한자 (hanja). Chinese is a very different language from Korean, and its script has thousands of characters. Learning to read and write it took years of study, which mostly only the yangban (aristocratic) class could afford.

There were workarounds, such as 이두 (idu), a system that borrowed Chinese characters to note Korean words and grammar. But these still needed a good knowledge of hanja, so farmers, servants and most women were left out.

What Sejong said in his preface

Sejong wrote a short preface himself, known as the 어제 서문 (eoje seomun, the royal preface). Here is a paraphrase in plain English, not a word-for-word translation:

Our country’s speech is different from China’s, so it does not match Chinese characters. Because of this, many common people have something they want to say but in the end cannot put their thoughts into writing. Feeling sorry for them, I have newly made 28 letters, so that everyone can learn them easily and use them comfortably every day.

Three ideas sit inside those few lines: Korean and Chinese are different languages, ordinary people were the ones suffering, and the new letters had to be easy. That last goal shaped every design choice.

How the letters were designed

In 1446 Sejong’s scholars published a companion book, the 훈민정음 해례본 (Hunminjeongeum Haerye-bon, the “explanations and examples” edition). It explains the logic behind each letter, which is unusual for any script.

The five basic consonants are pictures of the mouth making the sound:

Other consonants were made by adding strokes for a stronger sound: ㄱ gets a stroke and becomes ㅋ (k, with a puff of air), ㄴ becomes ㄷ and then ㅌ. So letters made in the same part of the mouth look related. You can see these families on the Hangul chart.

Vowels came from three symbols with a philosophical meaning: a dot ㆍ for heaven, a flat line ㅡ for earth, and a standing line ㅣ for a person. Combine them and you get the rest. A dot to the right of ㅣ gives ㅏ (a); a dot above ㅡ gives ㅗ (o). In modern Hangul the dot is written as a short stroke.

28 letters then, 24 now

Hunminjeongeum had 28 letters: 17 consonants and 11 vowels. Modern Korean uses 24 basic letters (14 consonants and 10 vowels). Four of the originals dropped out as the sounds of Korean changed:

• ㆍ (arae-a), a vowel whose sound merged into others; the letter stayed in spelling until the 1933 spelling rules dropped it
• ㆆ (yeorin hieut), a glottal stop-like consonant
• ㅿ (banchieum, also called 반시옷), a soft “z”-like sound
• ㆁ (yet-ieung), an “ng” sound, whose job was later taken over by ㅇ

You may still see ㆍ in brand names and old-style shop signs, used for a retro look.

A long wait to become mainstream

Inventing Hangul did not end the rule of Chinese characters. Many scholar-officials opposed it, and for centuries hanja stayed the script of government, law and scholarship. Hangul was used for letters, novels, poetry, Buddhist texts and instruction books, often by women, and some people called it 언문 (eonmun, “vernacular script”) with a slightly dismissive tone. In 1504 King Yeonsangun briefly banned it after anonymous notices criticizing him were written in Hangul.

Change came at the end of the 19th century. During the Gabo Reform of 1894, a royal decree made the national script the basis for official documents, alongside Chinese characters or mixed script. The name 한글 (Hangeul), “great script” or “Korean script”, became common in the early 20th century. After 1945, both Koreas made Hangul their main script, and today almost everything in Korea is written in Hangul, with hanja used only occasionally.

The rediscovered book

For centuries the Haerye edition was thought lost. A copy surfaced in Andong in 1940 and was bought by the collector Jeon Hyeong-pil (전형필), who kept it safe through the war. It is now held by the Kansong Art Museum and is a National Treasure of Korea (listed as No. 70 before Korea dropped heritage numbers in 2021). In 1997 UNESCO added it to the Memory of the World Register.

Hangul Day

South Korea celebrates 한글날 (Hangeullal, Hangul Day) on October 9, the date that marks the publication of Hunminjeongeum in 1446. It was first celebrated in the 1920s, removed from the list of public holidays in 1991, and became a day off again in 2013. North Korea calls its script 조선글 (Joseongeul) and marks 조선글날 (Joseongeullal) on January 15, a date tied to the alphabet’s creation rather than its publication.

If you want to see Sejong’s design for yourself, the quickest way is to learn the letters. Our plan for learning Hangul in a weekend walks you through it.

Sources: National Hangeul Museum (국립한글박물관) exhibition materials on Hunminjeongeum; National Institute of Korean Language (국립국어원) materials on Hangul and Hangul Day; UNESCO Memory of the World Register, “Hunminjeongeum Manuscript” (1997); Korea Heritage Service (formerly Cultural Heritage Administration), National Treasure No. 70.

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