Dien Bien Phu: The Battle That Ended an Empire in Asia

In late 1953 French commanders built a fortified base in the remote valley of Dien Bien Phu in northwest Vietnam, hoping to lure the Viet Minh into a set-piece battle and to block routes into Laos. They assumed the Viet Minh could not bring heavy artillery through the surrounding mountains. Giap's forces, aided by tens of thousands of porters carrying supplies by bicycle and on foot, hauled guns onto the heights and surrounded the base. The siege began on 13 March 1954.

Artillery soon closed the airstrip, the French garrison's lifeline. After 56 days the base fell on 7 May 1954, and around 11,000 French Union troops were taken prisoner. The defeat shocked France and came on the eve of an international conference at Geneva. It was widely seen as the first time a European colonial army had been defeated in a major set-piece battle by an anti-colonial movement, and it inspired nationalists elsewhere, including in Algeria.