On October 10, 1954, French troops folded up their flags and withdrew from their colonial capitol. As they left, Vietnamese communist forces entered the city, official ending 67 years of French occupation and effectively dismantling their holdings in SE Asia.
France had originally taken control of northern Vietnam following its defeat of China in the Sino-French War. Following their victories over the Chinese and Siam 9 years later, the French consolidated their SE Asian colonies into French Indochina which endured until the signing of the Geneva Accords in 1954 (which would ultimately set the stage for the American War).