고구려의 對唐戰爭과 遼西 및 동몽골 진출

Advance for Eastern Mongolia and Liaoxi of Koguryo through the War with Tang

This thesis starts from the year 640 A.D. to the year 650 A.D. of the Koguryo period, and is aimmed to explore the advance of Eastern Mongolia and Liaoxi of the Koguryo. New information in this thesis will be revealed as follows: This thesis inquired about the advance for Eastern Mongolia and Liaoxi of Koguryo during the invasion of Tang. That is, advancement of Eastern Mongolia and Liaoxi by the Koguryo during the year 640~650 was the battle of 644 A.D. and the battle of 653 A.D., and the battle of 654 A.D. The battle of 644 A.D. progressed in Yingzhou of Liaoxi. And, The battle of 653 A.D. progressed in Laohahe of Eastern Mongolia. The battle of 654 A.D. then progressed in a grassland of the Qidan in Eastern Mongolia. The battle of 653 A.D. was assumed to be originated from February to September. The soldiers of the Qidan built the Gyeonggwan in the battle of 654 A.D. This time, Sinsung of the Qidan was restricted by Tang. So far, this thesis has inquired about advancement for Eastern Mongolia and Liaoxi by Koguryo. Through it, one can know that Koguryo was controlled by nomadic tribes of the Qidan etc. But through a war with the Tang, Koguryo lost regulation of Qidan and arrived at a fall. Therefore, through the advancement for Eastern Mongolia and Liaoxi by Koguryo, one can learn very important historical events.