Who they were
Ngo Quyen was a general and the son-in-law of Duong Dinh Nghe, the autonomous governor of the Vietnamese lands. When his father-in-law was murdered by a rival who then called in the forces of Southern Han, Ngo Quyen moved against the usurper.
What they did
He crushed the usurper and met the Southern Han invasion at the Bach Dang River in 938, destroying the fleet with iron-tipped stakes hidden in the tidal riverbed. In 939 he proclaimed himself king, ruling from the old citadel of Co Loa. His reign was short: he died in 944, and the realm fell into the anarchy of the Twelve Warlords.
Legacy
Vietnamese historiography calls him the “founding father of independence,” the man who closed a millennium of Chinese rule. His Bach Dang stratagem became the national template, repeated against the Mongols in 1288.