They violated rule number 1: Underestimating the enemy
The French fought there from 1946-1954, and were defeated in what was later called North Vietnam at a place called Dien Bien Phu in 1954. Thus ending the war.
The French were defeated in the Dien Bien Phu battle in 1954. They were driven out then.
The French had fought there from 1946 to 1954; 1st Indochina War or French Indochina War.
The Vietnam War was the only time that the communists defeated an American supported free nation (South Vietnam).
Communist North Vietnam defeated South Vietnam
The peace conference that took place after the French were defeated by Ho Chi Minh produced the Geneva Accords. This was when Vietnam was officially divided into North and South Vietnam.
North Vietnam defeated the South (or the North conquered the South).
North Vietnam was a communist nation during the Viet War. They defeated (conquered) the Republic of South Vietnam during the Vietnam War (April 1975).
France. They left Vietnam after they were defeated by the Vietnamese at Dien Bien Phu. Lots of Vietnamese and French died during the battle.
The North invaded the South and defeated them (conquered them).
France was defeated.
The forces of the Republic of South Vietnam.