Chosongul Day

Chosongul (or Hangul, as it is known in South Korea) is a perfect alphabet—it features exactly one letter for every distinct sound in the Korean language—and is much admired for its design. This annual celebration of its invention in 1446 probably owes more to its remarkable genesis, however. King Sejong the Great sought to extend literacy beyond a small aristocratic elite by creating an alphabet more accessible than the classical Chinese characters that were standard at the time—an extraordinary concern for a 15th-century ruler. The enlightened king was an accomplished author who also strengthened Korean defenses against Japanese and Manchurian raiders and oversaw the invention of a sundial, a water clock, and a rain gauge.