Dae Jung-sang

Dae Jung-sang (625?-698?) was the contribute of Balhae, and the father of Dae Joyeong, who was the founder of Balhae. Though much of the credit for the founding of Balhae went to his son, many historians still give credit to Dae Jung-sang as the main supporter and leader in the founding of Balhae.

Background
Dae Jung-sang was born in Goguryeo. Many ancient Korean sources and the (Old) Book of Tang state that he was of the ethnic Goguryeo race, and was from a noble family that existed from the founding of Goguryeo.

Dae Jung-sang's service to Goguryeo is thought to have started when the Tang invaded Goguryeo in the second war of 661. General Dae Jung-sang was an active participant in this war and also helped defeat the Tang armies. Following the death of Yeon Gaesomun, the Tang invaded Goguryeo for a third time, and successfully conquered Pyeongyang in 668. Despite the fall of Pyeongyang, most of the territory of Goguryeo was not completely pacified and under Tang influence. As a result, revival movements resisted viciously against the Tang.

Goguryeo Revival movement
Most of the Goguryeo Aristocracy, including him, were taken to Yingzhou (Hanzi :營州), the homeland of the Khitan. Yingzhou became part of the Tang's General Protectorate to Pacify the East, and the Khitan were enraged.

In 696, the Khitan led a revolt that killed the cruel governor of the protectorate and gave Yingzhou back to the Khitan. Dae Jung-sang allied with the Baishan Mohe leader Geolsa Biu (Hangul: 걸사비우, Hanja: 乞四比羽 pinyin: Qǐsì bǐyǔ), and the two powers opposed the Tang in 698. The two leaders resisted the Tang's attack, but were forced to retreat. Both Geolsa Biu, and Dae Jung-sang died in battle, but Dae Jo-yeong led the remaining Goguryeo and Malgal soldiers and defeated the Tang army at the Battle of Cheonmun-ryeong and established the Balhae Empire.

Family
The most notable and famous of his children was his eldest, Dae Jo-yeong. Dae Jung-sang had another son, Dae Ya-bal (대야발), and probably also had other children besides Dae Jo-yeong because the Balhae Royal line consisted of two lineages, one from Dae Jo-yeong and the other from Dae Ya-bal.

Legacy
Dae Jung-sang's forgotten establishing of a Successor-state of Goguryeo laid the foundations for the founding of an even more powerful kingdom, which was Balhae. Despite all of his hard work, most people remember his son Dae Joyeong as the founder of Balhae. Nevertheless, his descendants continued on the Balhae Royal line to the fifteenth generation.

Though Balhae fell, it left a further legacy. The last princes of Balhae quickly gathered the Balhae Aristocracy and retreated to Goryeo for sanctuary. Taejo of Goryeo gladly took them in and the Dae family continued on and still survives to this day as the Hyeop-gye Tae clan (협계 태씨).