First Indochina War: Battle of Dien Bien Phu

Battle of Dien Bien Phu
French troops during the Battle of Dien Bien Phu. Public Domain

The Battle of Dien Bien Phu was fought from March 13 to May 7, 1954, and was the decisive engagement of the First Indochina War (1946-1954), the precursor to the Vietnam War. In 1954, French forces in French Indochina sought to cut the Viet Minh's supply lines to Laos. To accomplish this, a large fortified base was constructed at Dien Bien Phu in northwest Vietnam. It was hoped that the presence of the base would draw the Viet Minh into a pitched battle where superior French firepower could destroy its army.

Poorly sited in the low ground of the valley, the base was soon besieged by Viet Minh forces which used artillery and infantry assaults to grind down the enemy while also deploying a large number of anti-aircraft guns to prevent the French from resupplying or evacuating. In nearly two months of fighting, the entire French garrison was either killed or captured. The victory effectively ended the First Indochina War and led to the 1954 Geneva Accords which split the country into North and South Vietnam.


With the First Indochina War going poorly for the French, Premier Rene Mayer dispatched General Henri Navarre to take command in May 1953. Arriving in Hanoi, Navarre found that no long-term plan existed for defeating the Viet Minh and that French forces simply reacted to the enemy's moves. Believing that he was also tasked with defending neighboring Laos, Navarre sought an effective method for interdicting Viet Minh supply lines through the region.

Working with Colonel Louis Berteil, the "hedgehog" concept was developed which called for French troops to establish fortified camps near Viet Minh supply routes. Supplied by air, the hedgehogs would allow French troops to block the Viet Minh's supplies, compelling them to fall back. The concept was largely based on the French success at the Battle of Na San in late 1952.

General Vo Nguyen Giap. Photograph Source: Public Domain

Holding the high ground around a fortified camp at Na San, French forces had repeatedly beaten back assaults by General Vo Nguyen Giap's Viet Minh troops. Navarre believed that the approach used at Na San could be enlarged to force the Viet Minh to commit to a large, pitched battle where superior French firepower could destroy Giap's army.

Building the Base

In June 1953, Major General René Cogny first proposed the idea of creating a "mooring point" at Dien Bien Phu in northwest Vietnam. While Cogny had envisioned a lightly defended airbase, Navarre seized on the location for trying the hedgehog approach. Though his subordinates protested, pointing out that unlike Na San they would not hold the high ground around the camp, Navarre persisted and planning moved forward. On November 20, 1953, Operation Castor commenced and 9,000 French troops were dropped into the Dien Bien Phu area over the next three days.

Christian de Castries
Colonel Christian de Castries. US Army

With Colonel Christian de Castries in command, they quickly overcame local Viet Minh opposition and began building a series of eight fortified strong points. Given female names, de Castrie's headquarters was located in the center of four fortifications known as Huguette, Dominique, Claudine, and Eliane. To the north, northwest, and northeast were works dubbed Gabrielle, Anne-Marie, and Beatrice, while four miles to the south, Isabelle guarded the base's reserve airstrip. Over the coming weeks, de Castries' garrison increased to 10,800 men supported by artillery and ten M24 Chaffee light tanks.

Battle of Dien Bien Phu

  • Conflict: First Indochina War (1946-1954)
  • Dates: March 13-May 7, 1954
  • Armies and Commanders:
  • French
  • Brigadier General Christian de Castries
  • Colonel Pierre Langlais
  • Major General Rene Cogny
  • 10,800 men (March 13)
  • Viet Minh
  • Vo Nguyen Giap
  • 48,000 men (March 13)
  • Casualties:
  • French: 2,293 killed, 5,195 wounded, and 10,998 captured
  • Viet Minh: approx. 23,000

Under Siege

Moving to attack the French, Giap dispatched troops against the fortified camp at Lai Chau, forcing the garrison to flee towards Dien Bien Phu. En route, the Viet Minh effectively destroyed the 2,100-man column and only 185 reached the new base on December 22. Seeing an opportunity at Dien Bien Phu, Giap moved approximately 50,000 men into the hills around the French position, as well as the bulk of his heavy artillery and anti-aircraft guns.

The preponderance of Viet Minh guns came as a surprise to the French who did not believe that Giap possessed a large artillery arm. Though Viet Minh shells began falling on the French position on January 31, 1954, Giap did not open the battle in earnest until 5:00 PM on March 13. Utilizing a new moon, Viet Minh forces launched a massive assault on Beatrice behind a heavy barrage of artillery fire.

M24 Chaffees at Dien Bien Phu
French M24 Chaffee light tanks firing during the Battle of Dien Bien Phu, 1954. US Army

Extensively trained for the operation, Viet Minh troops quickly overcame French opposition and secured the works. A French counterattack the next morning was easily defeated. The next day, artillery fire disabled the French airstrip forcing supplies to be dropped by parachute. That evening, Giap sent two regiments from the 308th Division against Gabrielle.

Battling Algerian troops, they fought through the night. Hoping to relieve the beleaguered garrison, de Castries launched a counterattack north, but with little success. By 8:00 AM on March 15, the Algerians were forced to retreat. Two days later, Anne-Maries was easily taken when the Viet Minh were able to convince the T'ai (a Vietnamese ethnic minority loyal to the French) soldiers manning it to defect. Though the next two weeks saw a lull in fighting, the French command structure was in tatters.

The End Nears

Despairing over the early defeats, de Castries secluded himself in his bunker and Colonel Pierre Langlais effectively took command of the garrison. During this time, Giap tightened his lines around the four central French fortifications. On March 30, after cutting off Isabelle, Giap began a series of assaults on the eastern bastions of Dominique and Eliane. Achieving a foothold in Dominique, the Viet Minh's advance was stopped by concentrated French artillery fire. Fighting raged in Dominique and Eliane through April 5, with the French desperately defending and counterattacking.

Pausing, Giap shifted to trench warfare and attempted to isolate each French position. Over the next several days, fighting continued with heavy losses on both sides. With his men's morale sinking, Giap was forced to call for reinforcements from Laos. While the battle raged on the eastern side, Viet Minh forces succeeded in penetrating Huguette and by April 22 had captured 90% of the air strip. This made resupply, which had been difficult due to heavy anti-aircraft fire, next to impossible. Between May 1 and May 7, Giap renewed his assault and succeeded in overrunning the defenders. Fighting to the end, the last French resistance ended by nightfall on May 7.

French Prisoners at Dien Bien Phu
French prisoners of war are marched out of Dien Bien Phu, 1954. Public Domain


A disaster for the French, losses at Dien Bien Phu numbered 2,293 killed, 5,195 wounded, and 10,998 captured. Viet Minh casualties are estimated at around 23,000. The defeat at Dien Bien Phu marked the end of the First Indochina War and spurred peace negotiations which were ongoing in Geneva. The resulting 1954 Geneva Accords partitioned the country at the 17th Parallel and created a communist state in the north and a democratic state in the south. The resulting conflict between these two regimes ultimately grew into the Vietnam War.

mla apa chicago
Your Citation
Hickman, Kennedy. "First Indochina War: Battle of Dien Bien Phu." ThoughtCo, Apr. 5, 2023, Hickman, Kennedy. (2023, April 5). First Indochina War: Battle of Dien Bien Phu. Retrieved from Hickman, Kennedy. "First Indochina War: Battle of Dien Bien Phu." ThoughtCo. (accessed June 10, 2023).