The old name for the Red River was the Nhi River, 珥河, Erhe in Chinese. Crossing this river was the starting point for tributary missions to China.|
The Red River, the Song Ca - Mother River (Vietnamese), or Yuan River (Chinese), is the river that flows from southwestern China through northern Vietnam to the Gulf of Tonkin.
It begins in China's Yunnan province in the mountains south of Dali. It flows southeastward, passing through Dai ethnic minority areas before leaving China through Yunnan's Honghe Autonomous Prefecture. It enters Vietnam at Lào Cai Province. Once reaching the lowlands near Viet Tri, the river and its tributaries spread out to form the Red River Delta. It then flows by the Vietnamese capital, Hanoi, before emptying into the Gulf of Tonkin.
The reddish-brown heavily silt-laden water gives the river its name. It is notorious for its violent floods. The delta is the major agricultural area of northern Vietnam with vast areas devoted to rice. The land is protected by an elaborate network of dykes and levees.
In the 19th century, the river was thought to be a lucrative trade route to China. It was the forced opening of the Red River to European commerce that prompted the wars between France and the Vietnamese court from 1883 to 1886, culminating in the conquest of Vietnam by France.