Battle of the First Indochina War along Route Coloniale 4 (RC4, aka. Highway 4)
A decisive Việt Minh victory along RC4 that destroyed several French units and opened the Vietnam-China border to Communist supply lines.
Key Facts
- Date range
- 30 September – 18 October 1950
- Duration
- 19 days days
- Road contested
- Route Coloniale 4 (Highway 4)
- French units devastated
- Several battalions incl. Foreign Legion units
- Outcome
- French defeat; Việt Minh victory
By the Numbers
Location
Cause → Event → Consequence
France maintained a military base at Cao Bằng supplied via Route Coloniale 4, which had been subject to repeated Việt Minh ambushes from 1947 to 1949. The Việt Minh sought to clear the route to the Vietnam-China border to secure supply flows from the newly formed People's Republic of China, and to test large-scale offensive tactics not previously employed.
Between 30 September and 18 October 1950, Việt Minh forces, aided by China, launched a major offensive along Route Coloniale 4. Several French army units, including Foreign Legion battalions, were overwhelmed and effectively destroyed as combat formations, resulting in a decisive French defeat.
The battle opened the Vietnam-China border to a steady flow of Chinese military supplies to the Việt Minh, significantly strengthening their capacity for future operations. The destruction of multiple French units represented one of the worst French defeats of the First Indochina War and shifted momentum decisively toward the Việt Minh.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Side B
1 belligerent