The First Goryeo-Khitan War was a 10th-century conflict between the kingdom of Goryeo and the Liao dynasty ( the Khitan Empire ) near what is now the border between China and North Korea .

In 993 , the Khitan invaded Attack Goryeo 's northwest border with an army that the Liao commander claimed Statement to number 800,000 .

They forced Motion Goryeo to end Process_end its tributary relations with the Song dynasty , to become Becoming a Liao tributary state and to adopt Agree_or_refuse_to_act Liao 's calendar .

With Goryeo 's agreement Agree_or_refuse_to_act of these requirements , the Khitan withdrew Escaping .

Liao gave Giving Goryeo permission to incorporate Cause_to_amalgamate the land between the border of Liao and that of Goryeo , which was occupied Control by Jurchen tribes that were troublesome to Liao , up to the Yalu River .

Liao gave Giving Goryeo permission to incorporate Cause_to_amalgamate the land between the border of Liao and that of Goryeo , which was occupied Control by Jurchen tribes that were troublesome to Liao , up to the Yalu River .

In spite of the settlement , Goryeo continued to communicate Communication with Song , having strengthened Cause_change_of_strength its defenses by building Building fortresses in the newly gained Getting northern territories .