First conflict in the Goryeo–Khitan War
The First Goryeo-Khitan War was a 10th-century conflict between the kingdom of Goryeo and the Liao dynasty near what is now the border between China and North Korea. It occurred in 993 and was the first of the Goryeo-Khitan Wars, which were continued with the Second Goryeo-Khitan War and Third Goryeo-Khitan War.
In 993, the Khitan invaded Goryeo's northwest border with an army that the Liao commander claimed to number 800,000. They forced Goryeo to end its tributary relations with the Song dynasty, to become a Liao tributary state and to adopt Liao's calendar. With Goryeo's agreement of these requirements, the Khitan withdrew. Liao gave Goryeo permission to incorporate the land between the border of Liao and that of Goryeo, which was occupied by Jurchen tribes that were troublesome to Liao, up to the Yalu River. In spite of the settlement, Goryeo continued to communicate with Song, having strengthened its defenses by building fortresses in the newly gained northern territories.
