THE 5-SECOND TRICK FOR KOREA

Goryeo was invaded because of the Mongols in 7 major campaigns from your 1230s right up until the 1270s, but was hardly ever conquered.[117] Fatigued after decades of combating, Goryeo sent its crown prince for the Yuan funds to swear allegiance on the Mongols; Kublai Khan approved, and married amongst his daughters into the Korean crown prince,[11