Disturbances in Dai Viet had attracted attention from the Chinese Song Empire in the north. The emperor Taizong ordered Hou Renbao advance into Dai Viet territories, although Le Hoan had sent a message to the Song court which was declined. In early 981 the Chinese navy under Liu Cheng defeated Le Hoan's military on the Bạch Đằng River, killing 1,000 Viet sailors and seizing 200 junks. Hou Renbao urged his troops to march forward, but they didn't until Liu Cheng finally arrived and the Song land forces and navy regrouped at Da La village, then returned to Hoa Bo (Chi Lăng). Le Hoan pretended to surrender, tricked Hou Renbao to come, and then killed him and massacred his troops. The Song army was forced to retreated and their generals were punished with summary execution in Kaifeng for military failures. The Sung then sent three envoys in 986, 998 and 990 to Dai Viet, normalized the relations between two countries.