Sui And Tang Dynasties, Conquests Korea

Gaoli was one of the ancient minorities lived in the Northeast of China long ago , and was an early member of the Chinese Nation . From Han Dynasty to Tang Dynasty , they existed in the Northeast of China and the North of Korean peninsula, and devoted themselves to developing this area.In this endless history , Gaoli was friends with each minorities in the Northeast of Asia , but sometimes there were wars among them for the sake of their notional benefit . Sui-Tang Dynasties were used to conquest of Gaoli for nearly seventy years , the reasons of wich were considered as political and international relational questions by many scholars in the historical circle . I believe that what caused the war consisted of three part : First , the territoriality of Liaodong region made the contradiction between Gaoli and Chinese sharp ; Second , to obtain the domination over the minorities in the Northeast of Asia ; Third , the region of Liaodong impacts the safety and danger of the Central Plains of China.In that war , there were many similarities in directing the military operations between Sui Dynasty and Tang Dynasty, they often summarized the experiences of each campaign carried out previously , so as to made their policies ,diplomatic guiding and military plans about the war better . For this reason , I think that conquest of Gaoli carried out by Sui Dynasty and Tang Dynasty should be considered as one question in its entirety.There were some differences in the military regulatins between Sui Dynasty and Tang Dynasty , so the consequences of the two Dynasties' conquests of Gaoli were not alike .Sui Dynasty ruined because much more manpower and materiel were depleted in the war . Thoug Tang Dynasty also costed heavily for it , the final success was good to the stability of the Northeast of Asia and the development of each nation in the area.