Balhae Empire of Korean Peninsula

Balhae (698–926) was a kingdom in present-day Manchuria and northern Korean peninsula. Balhae was established by former Goguryeo(a kingdom of Korea) general Dae Jo-yeong in 698 after his defeat of the Tang Chinese at Tianmenling. Balhae's original capital was at Dongmo Mountain in modern Dunhua, Jilin Province.

Bridge of Tumen City, Jilin Province, China

Dae Joyeong, also known as King Go, established the state of Balhae, reigning from 699 to 719. He was the was the first son of general Dae Jung-sang of Goguryeo. He claimed himself the King of Jin in 698. He established his capital at Dongmo Mountain in the south of today's Jilin province, and built Dongmo mountain fortress, which was to become Jin's capital. Dae Jo-yeong died in 719, and his son Dae Muye assumed the throne. Dae Jo-yeong was given the posthumous name "King Go."

Lake Dongmo

Dae Mu-ye, also known as King Mu (r. 718–737), was the second king of the Balhae in Korean peninsula. Balhae's aggressive expansion triggered frictions with Tang China, Silla of southern Korea, the Khitans, the Xi, the Göktürks, and several Mohe tribes. In 727, Balhae began to dispatch embassies to Japan to avoid international isolation. Japan, whose relationship with Silla was strained, welcomed them as a revival of Goguryeo. Dae Muye was succeeded by his son Dae Heummu in 737.

A temple in Japan

King Mun of Balhae (r. 737–793),was the third and longest-reigning ruler of the Balhae in Korean peninsula, the successor state to Goguryeo. During King Mun's reign, diplomatic ties with Tang Dynasty China were established.  He also strengthened relations with Silla, which unified the Korean peninsula to the south of Balhae. Balhae also increased diplomacy and trade with Japan.

Tang China Painting

Dae Won-ui (died 793) (r. 793) became the 4th ruler of the kingdom of Balhae. However, upon ascending the throne the king showed a jealous and violent temper. In 793, he was slain by his ministers. The son of Goeng-rim was chosen to replace him, becoming King Seong. The most notable accomplishment that was done during his reign was the moving of the capital to Sanggyeong. Gang of Balhae (died 809) (r. 794–809) was the sixth to rule the king of Balhae.

Within 10 years of death of King Gang of Balhae (died 809), the state was ruled by three kings who were Jeong of Balhae(r. 809 - 812 CE) , Hui of Balhae(r. 812 - 817 CE) and Gan of Balhae(r. 817 - 818 CE) who ruled as the 7th, 8th and 9th king of Balhae. The tenth King Seon reign (r. 818–830), Balhae controlled northern Korea, Northeastern Manchuria and now Primorsky Krai of Russia.

Primorsky Krai

During King Seon's 12-year reign, he dispatched embassies five times to Japan, which was aimed at establishing diplomatic relations as well as increasing trade between the two kingdoms. The trade routes established across the Sea of Japan (East Sea) led to Balhae becoming one of Japan's most important trading partners. He died in 830 and his grandson Dae Ijin succeeded to the throne.

Sea of Japan(East Japan)

Dae Ijin (r. 830–857) was the 11th king of Balhae, a Korean kingdom from AD 698 to 926, occupying parts of Manchuria and northern Korea. The king made efforts for the consolidation of a centralized administrative system and organized a standing army. He was succeeded by Geonhwang of Balhae (r. 857-871) who sent a few missions to Japan and Tang China.

Dae Hyeonseok, was the 13th king of Balhae who reigned from 871 to 894. He was succeeded by Dae Wihae (r. 894–906 CE) who was succeeded by Dae Inseon  (r. 906–926 CE). This was a time of momentous change for Balhae and its neighbors. In China, the Tang faced serious crises caused by the An Lushan Rebellion and many other uprisings. Finally, Zhu Wen established the Later Liang, marking the end of the Tang dynasty in 907.

King Dae concentrated on increasing defense capabilities against the threat of new powers and was in favor of allying with the Goryeo Dynasty. However, the interference of the nobility did not allow that to happen. The Khitans' growing power in Manchuria was the most threatening to Balhae. Eventually, they invaded Balhae in 925 and the capital Sanggyeong (also known as Holhan fortress) fell after ten days. In 926, Balhae came to an end, while many of the nobility fled to Goryeo.

After the fall of Balhae and its last king in 926, it was renamed Dongdan by its new Khitan rulers. Restoration movements by displaced Balhae people established Later Balhae, which was later renamed to Jeongan. Dae Gwang-hyeon, the last crown prince, and much of the ruling class of Balhae sought refuge in Goryeo, where they were granted land and the crown prince included in the royal household by Wang Geon, thus unifying the two successor nations of Goguryeo.