Da Renxiu (大仁秀 Dà Rénxìu) or King Xuan (宣王) (r. 818?-830) was the 10th king of Bohai. He restored national strength.
He was a 4th-generation descendant of Da Zuorong's brother. In spite of the collateral root, he succeeded to the throne around 817 and 818. He recaptured royal authority and took a number of military operations northward against Mohe tribes and southward against Silla.
During his 12 year reign, he dispatched embassies five times to Japan, which aimed at trade in the name of laying tribute. Bohai's articles won favorable recognition in Japan although she tried to restrict the dispatchment due to the excessive burden of reception. The Japan-Bohai line across the Sea of Japan became one of important routes toward Tang for Japan.
He died in 830 and his grandson Da Yizhen succeeded to the throne.
Bohai was founded by Da Zuorong of the Sumo Mohe tribe and integrated several Mohe tribes and Goguryeo remnants.
The second king Da Wuyi (King Wu), who felt encircled by Tang, Silla and Black Water Mohe along the Amur River, attacked Tang and his navy briefly occupied a port on the Shandong Peninsula in 732.
The third king Da Jinmao (King Wen) expanded its territory into the Amur valley in the north and the Liaodong Peninsula in the west.