Battle of Dien Bien Phu

In a remote valley of north-western Vietnam, close to the border with Laos, the Viet Minh besieged and destroyed a French fortified base in the spring of 1954, from 13 March to 7 May. Dien Bien Phu proved to be the battle that decided the First Indochina War. It shocked public opinion in France, hastened the end of French rule in French Indochina, and was hailed across the colonial world as proof that a European power could be beaten by an army of the colonised.

By 1953 years of war had failed to defeat the Viet Minh, the communist-led independence movement headed by Ho Chi Minh, which had pushed deep into Laos. The new French commander, General Henri Navarre, adopted a "hedgehog" concept: a strongly fortified base supplied entirely by air, planted on the enemy's supply lines to Laos. The French hoped to repeat their success at Nà Sản in 1952, where Viet Minh frontal attacks on a similar camp had been beaten off with heavy losses. Dien Bien Phu, with an old airstrip built by the Japanese, was chosen despite the objections of several senior officers.

Operation Castor began on 20 November 1953, when the French dropped or flew in about 9,000 troops over three days. Under Colonel Christian de Castries, they built a central headquarters ringed by strongpoints with women's names such as Béatrice, Gabrielle, Anne-Marie, Huguette, Dominique, Eliane and, to the south, Isabelle. But much of the hilly ground ringing the valley remained in Viet Minh hands. Their commander, General Võ Nguyên Giáp, spent months hauling heavy artillery and anti-aircraft guns over difficult terrain and dug them into the hillsides, where French guns could not reach them. He abandoned a plan for a quick assault in January in favour of a methodical siege, a change he later called the hardest decision of his career.

The attack opened on 13 March 1954 with a fierce bombardment of Béatrice, which fell in the early hours of 14 March. Gabrielle was lost by the morning of 15 March, and on 17 March most of the Tai troops holding Anne-Marie left or defected. Artillery closed the airstrip, so from then on all supplies and reinforcements had to come by parachute, while anti-aircraft fire took a heavy toll on French aircraft. Through April the battle became a grinding contest of trenches and counter-attacks, as the perimeter steadily shrank.

Massed Viet Minh assaults on 1 May overran several more positions, and on 6 May a mine was detonated beneath Eliane 2. On 7 May, Giáp ordered a general attack. The headquarters fell that evening, and the last strongpoint surrendered that night. By the Viet Minh's count they took 11,721 prisoners, 4,436 of them wounded. Forced to march hundreds of kilometres to camps, many died; four months later, only 3,290 were handed back.

French records to 5 May list 1,142 killed in action, 429 dead of wounds and 1,606 missing; other sources give around 2,293 killed. The Vietnamese government reported its own losses as 4,020 dead and 9,118 wounded, with 792 missing. French estimates were higher, at about 8,000 dead and 15,000 wounded.

The Geneva Conference on Indochina opened on 8 May, the day after the surrender. In July it agreed to divide Vietnam temporarily at the 17th parallel, with the communist Democratic Republic of Vietnam in the north and the State of Vietnam in the south, pending elections in 1956 that were never held. The partition set the stage for the Vietnam War. News of the defeat spread quickly through France's other colonies; Ferhat Abbas, later head of the Algerian provisional government in exile, a country that fought its own Algerian War against France, called it the "Valmy" of the colonised peoples.

Our 1945 map shows French Indochina before the war, and our 1960 map shows Vietnam divided into North and South after the Geneva agreements.