Outbreak of the Goryeo-Khitan War

Timeline

1. 1010Yalu River line · KoreaLiao's Emperor Shengzong sent a great army across the Yalu River southward, launching a second large-scale invasion on the grounds of Goryeo's earlier refusal of tribute and border conflicts; Liao forces quickly broke through the northern defenses and advanced on the royal capital.
2. 1010Kaesong · KoreaLiao forces reached Kaesong, and Goryeo's King Hyunjong at one point relocated south to Naju, shocking the court. Defending generals organized the city's defenses while mustering local troops and militia to slow the Liao advance.
3. 1010Battlefield north of Kaesong · Korean PeninsulaGeneral Gang Hangzan led a counterattack, combined with scorched-earth tactics and guerrilla harassment; Liao forces withdrew northward due to overextended lines and failing supplies. After the war Goryeo restored tribute relations with Liao, but northeastern frontier pressure continued.