Mun (; 715âÂÂ793; ), also known as Tae Hà Âmmu, was the third and longest-reigning ruler of the Balhae. He succeeded his father King Mu, upon his death in 737. He was the grandson of Tae Choyà Âng, the founder of Balhae.
During King Mun's reign, diplomatic ties with the Tang dynasty were established, and many Balhae scholars went to the Tang to study, extending the influence of Buddhism and Confucianism in Balhae's governance. He also strengthened relations with Silla, which unified the Korean peninsula to the south of Balhae, overseeing the development of the trade route called Silla-road (). Balhae also increased diplomacy and trade with Japan.
King Mun moved the capital of Balhae several times (Sanggyeong and Donggyeong), stabilizing and strengthening central rule over various ethnic tribes in his realm, which was expanded temporarily. He also authorized the creation of the Chujagam (), the national academy, based on the national academy of Tang.
Although the Tang dynasty recognized him as a king, Balhae itself referred to him as the Taehà Âng poryà Âk hyogam kà Âmnyun sà Ângbà Âp taewang (, 大èÂÂ寶æÂÂÃ¥ÂÂæÂÂéÂÂ輪èÂÂæ³Â大çÂÂ), Kadokpu (), Seongwang () and Kiha (), Balhae itself referred to him as the posterity of heaven and an emperor.
The tomb of his fourth daughter, Princess Chà Ânghyo, was discovered in 1980. The tombstone of his elder daughter, Princess Chà Ânghye, has also been found.