Dangun

Dangun Wanggeom (or Tangun) was the legendary founder of Gojoseon (Gochoson or Old Choson), the first Korean state which ruled northern Korea in the second half of the first millennium BCE. Gojoseon possessed the most advanced culture in the Korean peninsula at that time and was an important marker in the progression towards the more centralised states of later periods. According to mythology, Dangun was born on the third day of the tenth month and so the 3rd of October is celebrated as National Foundation Day in modern South Korea.