Battle of Bạch Đằng: Ngô Quyền defeats the Southern Han

After the fall of the Tang the former protectorate of Annam, the Jinghai army, was ruled by local governors. In 930 the Southern Han, a kingdom based at Guangzhou, took its capital and carried off the governor Khúc Thừa Mỹ, but in 931 Dương Đình Nghệ, an officer from Ái châu (Thanh Hóa), drove out the Han garrison. After Kiều Công Tiễn murdered Dương in the spring of 937, Dương’s general and son-in-law Ngô Quyền marched from Ái châu against him in 938, and Kiều sought help from the Han with bribes. The Han ruler Liu Yan saw a chance to take the country: he made his son Liu Hongcao, Prince of Wan, military governor of Jinghai and sent him with a fleet, while he himself camped at Haimen in support, ignoring his minister Xiao Yi, who warned that the long rains, the dangerous sea route and the cunning of Ngô Quyền called for caution.

The Zizhi tongjian, compiled in 11th-century China, gives a detailed account of the battle. By the time Hongcao sailed up the Bạch Đằng (Baiteng), Ngô Quyền had already killed Kiều Công Tiễn and taken the city. He had large stakes, sharpened and capped with iron, planted at the river mouth, and sent light boats to provoke the enemy on the rising tide and then feign flight; Hongcao pursued, the tide fell, and the Han warships, caught on the stakes, could not turn back. More than half the Han soldiers were drowned, Hongcao died, and Liu Yan, weeping bitterly, led the rest home. The Vietnamese Đại Việt sử ký toàn thư (1479) tells the same story, adds a speech in which Ngô Quyền devises the stratagem and says that he captured Hongcao and put him to death; a later Vietnamese chronicle has Hongcao drown.

In the spring of 939 Ngô Quyền proclaimed himself king (vương), made his wife, of the Dương family, queen, appointed officials and set up his court at Cổ Loa, the ancient citadel near present-day Hanoi; he reigned until his death in 944. The 13th-century historian Lê Văn Hưu wrote that under him ‘the orthodox line of our country was almost restored’. The Zizhi tongjian places the events under the 10th lunar month of the third year of Tianfu (26 October – 24 November 938); the Toàn thư dates Ngô Quyền’s march from Ái châu to the 12th month of the same lunar year (24 December 938 – 22 January 939), so the battle may already have taken place in January 939.