[3][4] Their power waned with Ngô Quyền's death in 944 and a civil war in 958 that split the realm into the domains of twelve warlords.

In 971, the Song emperor ordered the subjugation of Lingnan (the lands south of the passes), which implicitly included Đại Cồ Việt.

In addition, the Song dynasty sent troops under Hou Renbao to invade Đại Cồ Việt under the pretext of removing threats to the young emperor's rule.

In response the Viet court urged Lê Hoàn to become king, pacify the countryside, and prepare for the Song invasion.

[1][8] In early 981, two Song armies attacked Đại Cồ Việt through land, and a fleet of ships sailed up the Bạch Đằng River.