Mun of Balhae " King Mun of Balhae " ( r. 737–793 ), also known as " Dae Heum-mu ", was the third and longest-reigning ruler of the Balhae, the successor state to Goguryeo
During King Mun's reign, diplomatic ties with Tang Dynasty China were established, and many Balhae scholars went to China to study, [ http: xenohistorian....
Diplomacy
Emperor Mun moved the capital of Balhae several times(Sanggyeong and Donggyeong) , ... The extension of Balhae Kingdom under King Mun (Korean) ...