Jeongan
Jeongan or Ding'an (; ; 938–986) was a successor state of Balhae (Bohai) founded by Yeol Man-hwa. The official Chinese historical record, the "History of Song" states that Jeongan people's origin can be traced back to the former confederacy of Mahan. Establishment and Downfall. When Khitan-led Liao dynasty forces deposed Balhae in 926, a few officials of the fallen kingdom, led by the Dae clan, established Later Balhae in 929. However, in 935, General Yeol Manhwa took control of the government after the death of the Dae clan king, and changed the state name to Jeongan. Jeongan is  recorded to have enlisted the assistance of neighboring tribes with the hopes of overthrowing the Liao dynasty, but apparently failed to do so. The Yeol clan was replaced by the Oh clan in 976, and was ruled by Oh Hyeon-myeong until before it was finally destroyed by the Liao dynasty in 986 CE.