Battle of Route Coloniale 4 was a campaign in the First Indochina War carried out by the Việt Minh Army from 16 September to 17 October 1950 to break the isolation of the Việt Bắc base, clear the Vietnam-China border Bridge to receive aid. Another objective was to expand the base and destroy some of the French garrison force, experimenting with tactics for the People's Army of Vietnam at that time with little experience in combat.