함경북도
When King Sejong drove the Jurchen from what is now the northernmost part of North Hamgyong Province in 1434, he established six garrisons ("Yukchin") in the bend of the Tumen River – Kyŏnghŭng, Kyŏngwŏn, Onsŏng, Chongsŏng, Hoeryŏng and Puryŏng – populated by immigrants from southeastern Korea.