<Li> Điện Biên Phủ </Li> <Li> Mang Yang Pass </Li> <P> The Battle of Dien Bien Phu (French: Bataille de Diên Biên Phu; Vietnamese: Chiến dịch Điện Biên Phủ, IPA: (ɗîəˀn ɓīən fû)) was the climactic confrontation of the First Indochina War between the French Union's French Far East Expeditionary Corps and Viet Minh communist - nationalist revolutionaries . It was, from the French view before the event, a set piece battle to draw out the Vietnamese and destroy them with superior firepower . The battle occurred between March and May 1954 and culminated in a comprehensive French defeat that influenced negotiations underway at Geneva among several nations over the future of Indochina . </P> <P> As a result of blunders in French decision - making, the French began an operation to insert, then support, the soldiers at Điện Biên Phủ, deep in the hills of northwestern Vietnam . Its purpose was to cut off Viet Minh supply lines into the neighboring Kingdom of Laos, a French ally, and tactically draw the Viet Minh into a major confrontation in order to cripple them . The plan was to resupply the French position by air, and was based on the belief that the Viet Minh had no anti-aircraft capability . The Viet Minh, however, under General Võ Nguyên Giáp, surrounded and besieged the French . The Viet Minh brought in vast amounts of heavy artillery (including antiaircraft guns). They moved these weapons through difficult terrain up the rear slopes of the mountains surrounding the French positions, dug tunnels through the mountain, and placed the artillery pieces overlooking the French encampment . This positioning of the artillery made it nearly impervious to French counter-battery fire . </P>

When was the battle of dien bien phu and what was the result