That Khe is 67 km from Cao Bang, 65 km from Lang Son, and about 20 km to the Chinese border.
On September 16th five Viet Minh infantry and one heavy weapon battalions attacked Dong Khé. It was then garrisoned by some 300 French troops comprising the 5th and 6th companies of the 2nd battalion of the 3rd Regiment of the French Foreign Legion (3rd REI). On September 18th the fort was overrun after bitter fighting. In reality, only 12 survivors escaped to the nearby post at That Khé. 140 Legionnaires had been taken the prisoner, the remainder being killed or missing in action.
That Khé was quickly reinforced by the Foreign Legion’s 1st Parachute Battalion (1st BEP), which parachuted in on September 17th. The 1st BEP waited at That Khe while a force of French colonial troops, the Moroccan 1st and 11th Tabors, assembled at Lang Son. Designated Groupement Bayard the combined force comprised 3,500 men under the command of Colonel Le Page. The task force launched an intelligence raid, capturing prisoners who said a massive Viet Minh offensive was planned.
The road between Dong Khe and That Khe is one of the most challenging parts of Northeast Vietnam. In fact, it is either dusty and bumpy or wet and muddy. Be prepared for this dirt track.
For more information about places, people, or things that are useful in planning your motorbike tour in Vietnam, please follow this link