The Goryeo dynasty (935-1392) first called the mountain Paektu, recording that the Jurchens across the Yalu River were made to live outside of Mount Paektu. The Joseon Dynasty (1392-1910) recorded volcanic eruptions in 1597, 1668, and 1702. In the 15th century, King Sejong the Great strengthened the fortification along the Tumen and Yalu rivers, making the mountain a natural border with the northern peoples. Some Koreans claim that the entire region near Mount Paektu and the Tumen River belongs to Korea and parts of it were illegally given away by Japanese colonialists to China through the Gando Convention.