Yi Seong-gye, founder of the Yi Dynasty, retired to the city after a successful palace coup by his son Yi Bang-won in 1400. Though his son sent envoys to reconcile, his father had them killed. A modern Korean expression, 'King's envoy to Hamhŭng' (), refers to a person who goes on a journey and is never heard from again. It was known as "Kankō" during Japanese rule of Korea between 1910 and 1945. It was liberated by the Red Army on 22 August 1945.