October 3 is the birthday of Tangun, father of the Korean nation.
From ancient times the Korean people declared the birthday of Tangun as the National Foundation Day and have been commemorating it. The original meaning of the Korean word means the opening of the sky, that means foundation of the state.
Tangun was born as son of a Chief in present Pyongyang more than 5,000 years ago. In his childhood and youth he trained hard martial arts including archery, spearmanship and fencing and studied hard to understand nature and society. Tangun who had a huge build and clever brain, distinguished himself in martial arts and had a great ambition to transform and change the society. Afterwards he became the chief of the tribe, following in the footsteps of his father. He built the first ancient state on this land in the early 30th century B.C. and called it Korea. The name of the ancient state is called ancient Korea in order to distinguish it from Korea built afterwards. As the first slave state ancient Korea set up the capital in Pyongyang and merged the neighbouring tribes by strengthening national power and occupied the vast land of northeast Asia, expanding the sphere of its power. It was known as a powerful country externally. As Tangun built the country the Korean nation got rid of the long primitive times and entered the era of statehood, the era of civilization earlier than others in the East. Ancient Korea existed for nearly 3,000 years. Afterwards successive feudal states including Koguryo and Koryo succeeded to ancient Korea. Tangun was buried in darkness of history as a mythical man owing to the Japanese imperialists´ moves to distort the Korean history and obliterate the Korean nation during the Japanese imperialist colonial rule in the first half of the past 20th century. But thanks to the correct policy of the WPK on unearthing and preserving national cultural heritages Tangun was scientifically confirmed as a real person and the Mausoleum of King Tangun was grandly reconstructed.
Every year on October 3, the National Foundation Day, various functions including memorial service of Tangun are held at the Mausoleum of King Tangun according to the long customs of the Korean nation.