<P> The battle began on March 13 when a preemptive Viet Minh attack surprised the French with heavy artillery . The artillery damaged both the main and secondary airfields that the French were using to fly in supplies . The only road into Điện Biên Phủ, already difficult to traverse, was also knocked out by Viet Minh forces . With French supply lines interrupted, the French position became untenable, particularly when the advent of the monsoon season made dropping supplies and reinforcements by parachute difficult . With defeat imminent, the French sought to hold on until the opening of the Geneva peace meeting on April 26 . The last French offensive took place on May 4, but it was ineffective . The Viet Minh then began to hammer the outpost with newly supplied Soviet Katyusha rockets and other weaponry provided by communist allies . </P> <P> The final fall took two days, May 6 and 7, during which the French fought on but were eventually overrun by a huge frontal assault . General Cogny, based in Hanoi, ordered General de Castries, who was commanding the outpost, to cease fire at 5: 30 pm and to destroy all materiél (weapons, transmissions, etc .) to deny their use to the enemy . A formal order was given to not use the white flag so that the action would be considered a ceasefire instead of a surrender . Much of the fighting ended on May 7; however, the ceasefire was not respected on Isabelle, the isolated southern position, where the battle lasted until May 8, 1: 00 am . </P> <P> At least 2,200 members of the 20,000 - strong French forces died, and another 1,729 were reported missing after the battle, and 11,721 were captured . Of the 50,000 or so Vietnamese soldiers thought to be involved, there were an estimated 4,800 to 8,000 killed and another 9,000--15,000 wounded . The prisoners taken at Điện Biên Phủ were the greatest number the Viet Minh had ever captured: one - third of the total captured during the entire war . </P> <P> One month after Điện Biên Phủ, the composite Groupe Mobile 100 (GM100) of the French Union forces evacuated the An Khê outpost and was ambushed by a larger Viet Minh force at the Battle of Mang Yang Pass from June 24 to July 17 . At the same time, Giap launched some offensives against the delta, but they all failed . The Viet Minh victory at Điện Biên Phủ heavily influenced the outcome of the 1954 Geneva accords that took place on July 21 . In August Operation Passage to Freedom began, consisting of the evacuation of Catholic and loyalist Vietnamese civilians from communist North Vietnamese persecution . </P>

Who led the movement for vietnam's independence from french rule