Hunminjeongeum

The ninth lunar month of 1446

During the ninth lunar month of 1446, King Sejong's government completed and published the Hunminjeongeum, formally presenting the Korean alphabet Sejong had completed in 1443.

The Veritable Records of King Sejong say the work was completed 'this month' and reproduce Sejong's explanation of the letters, their sounds, syllable formation and tone marks. No source fixes publication to one verified day.

Where 9 October came from

Jeong In-ji's postface is dated to the first ten days of that month, not specifically to its tenth day. The modern observance was obtained by taking the last day of that interval and converting it to the solar calendar.

October 9 is therefore a commemorative date. The strongest event date the sources support is October 1446.

What was in the book

The published Haerye edition combined Sejong's proclamation with explanations and examples prepared by Hall of Worthies scholars, closing with Jeong In-ji's postface.

The proclamation did not merely list letters. It told readers which vowels went below an initial consonant and which went to its right. The original alphabet had 28 letters, four more than the 24 basic letters of modern Korean.

It was a publication milestone rather than a replacement of Chinese-character writing: official documents remained predominantly in Hanja until Hangeul became the official national writing system in 1894.