The Shilla dynasty that had ruled most of Korea since 678 as a nominal vassal of China after fighting the T’ang to a standstill was replaced in 918 by the Koryo, who expanded their rule north to the Yalu river. The Khitan attacked them in 993, and penetrated deep into Korea before being fought to a draw. Further invasions in 1010 and 1018 ended similarly. After the establishment of the Jurchen-Chin dynasty in 1115 in China, they became tributary to it. They fought against Mongol invasions 1231-1273, some forces assisting the Mongols but others waging guerrilla warfare from the hills, often against Koryo dynasty orders. The dynasty ended in 1392 after a general, Yi Song-gye, refused to follow orders to help the Mongols against Ming China, revolted and founded the Yi dynasty. Reference: Generals and Scholars: Military Rule in medieval Korea Edward Schultz.
— Koryo Dynasty Korean Army 918 AD - 1392 AD
II/77 — SHILLA KOREAN 300 AD - 935 AD
III/39 — LATE T’ANG & FIVE DYNASTIES CHINESE 755 AD - 979 AD
III/55 — EARLY SAMURAI 900 AD - 1300 AD
III/56 — KHITAN-LIAO 907 AD - 1125 AD
III/62 — SUNG CHINESE 960 AD - 1279 AD
IV/14 — JURCHEN-CHIN 1114 AD - 1234 AD
IV/35 — MONGOL CONQUEST 1206 AD - 1266 AD
IV/48 — YUAN CHINESE 1260 AD - 1368 AD
IV/59 — POST-MONGOL SAMURAI 1300 AD - 1542 AD
IV/14 — JURCHEN-CHIN 1114 AD - 1234 AD
IV/48 — YUAN CHINESE 1260 AD - 1368 AD