Da Wuyi (大武藝), also known as King Wu (武王) (r. 718-737), was the second king of Bohai. He expanded his domain with force.
He was a son of Da Zuorong, the founder of Bohai and succeeded to the throne after his father's death in 718. He gave the posthumous title King Gao his father and declared the era name Ren'an at his own choice, which was considered impudent for the Tang Dynasty. On the other hand, he frequently sent embassies to the Tang, including his sons and brothers.
Bohai's aggressive expansion triggered frictions between various entities including the Tang, the Khitans, the Xi, Gokturk, Silla and several Mohe tribes. When the Heisui Mohe in the north of Bohai came under the direct control of the Tang in 727, Da Wuyi attacked the Heisui Mohe fearing a pincer attack. His pro-Tang brother Da Menyi opposed the military campaign and defected to the Tang. In 732 Da Wuyi made Zhang Wenxiu raid Shandong with the navy (called "pirates" in Chinese documents). The Tang ordered Da Menyi to make a counterattack and Silla to attack from the south.
To avoid international isolation, Da Wuyi began to dispatch embassies to Japan in 729. Japan welcomed them as a revival of what it considered to be the tributary Goguryeo, although Bohai assumed by mistake that Bohai and Japan were equal under the Tang's suzerainty.
In 735 the Tang accepted Da Wuyi's apology to incorporate Bohai into its anti-Gokturk alliance. Bohai enthusiastically introduced Tang's culture again although the tension with Silla remained high. He died in 737 and his son Da Qinmao succeeded to the throne.
