Balhae (698-926) was a country established around Mt. Dongmo by Daejoyong who gathered the migrants of Goguryeo. Balhae in its heyday occupied a broad territory covering the north of Daedong River of the Korean peninsula, Liaoning (遼寧省), Jilin (吉林省), and

Heilongjang (黑龍江省) of China and the Maritime Province of Russia. It formed a culture so developed that China praised the “Thriving nation of the Eastern sea” and maintained a range of institutions by actively adopting advanced civilization. To effectively rule the wide

territory, Balhae had five gyeong (provinces) and moved the capital city several times. In the capital cities, Sanggyeong, Jungeyong and Dongygong, there were well-built architecture, splendidly decorated roof tiles, bricks, dragon heads, potteries, weapons, various Buddhist

status, etc. excavated showing a highly developed Balhae culture. Balhae developed in active exchange not only with Tang Dynasty and Silla but also with Japan. After the fall of Balhae, some of the migrants joined Goryeo and sustained the legacy in Korean history.