The Three Heavenly Tokens of Hwanung
The Samguk Yusa's account of Gojoseon records that when Hwanin saw his son Hwanung longing to govern the human world, he looked down upon Samwi and Taebaek, judged that his son could 'broadly benefit humankind,' and 'gave him three Cheonbuin, heavenly seals, and sent him to rule.' With these tokens Hwanung led the lords of wind, rain, and clouds and founded the City of God beneath the divine tree on Mount Taebaek. That single sentence is all the text spares them: their number is three, their function is warrant of heaven's mandate, and of their form not one word.
The blank has invited seven centuries of guesswork. The commonest conjecture makes them a sword, a mirror, and a bell, on the grounds that Korean shamans to this day summon the gods with exactly that triad of implements, the spirit knife, the bright mirror called myeongdu, and bronze bells; others argue by analogy with Japan's three imperial regalia. Bronze Age finds are pressed into service as footnotes, and the fine-lined bronze mirrors, eight-belled rattles, and bronze daggers unearthed in Korea are routinely likened to the seals in museums and popular books. All of this is later reading; the original supports none of it and contradicts none of it.
As an emblem of heavenly mandate the Cheonbuin has been much requisitioned in modern times. Daejonggyo, the Dangun-venerating national religion founded in 1909, absorbed it into its symbolism, and historical fiction and television gladly hand the hero three tangible treasures.

