Battle of Dien Bien Phu, climactic battle of the First Indochina War (1946-1954), fought between the French and the Viet Minh, a nationalist group seeking independence from French colonial rule. The battle took place in 1954 at the town of Dien Bien in northwestern Vietnam, near the country’s border with Laos. The defeat of the French led to the signing of peace agreements that set the terms for ending the war.

The French reinforced their garrison at Dien Bien in November 1953 to prevent the Viet Minh from gaining control of northern Laos and the middle and lower Mekong River Valley. The outpost was strategically linked to the cities of Hanoi, in northern Vietnam, and Louangphrabang, in northern Laos. The Viet Minh, led by General Vo Nguyen Giap, began attacking the French at Dien Bien on March 13, 1954. The base was finally overrun by the Viet Minh forces on May 7, 1954.

The battle forced the French to negotiate peace agreements at a conference held in Geneva, Switzerland, and the war was brought to an end on July 20, 1954. According to the terms of the agreements, known as the Geneva Accords, Vietnam was temporarily divided at the 17th parallel into North Vietnam and South Vietnam. The French relinquished control of North Vietnam to a Communist government led by Viet Minh leader Ho Chi Minh. South Vietnam remained under the government of Bao Dai, the former Vietnamese emperor who had been named as head of state by the French during the war.