Short answers, pulled from the story.
The First Indochina War began on the 19th of December 1946 and ended on the 11th of August 1954, lasting nearly eight years. The war was fought between France and the Viet Minh in French Indochina, with most engagements occurring in Vietnam.
The Battle of Dien Bien Phu was the last major battle of the First Indochina War, fought in a valley in northern Vietnam from March to May 1954. The Viet Minh under General Vo Nguyen Giap encircled 15,000 French troops with more than 40,000 of their own, cutting off French airfields and supply lines until French forces were overrun. At least 2,200 French troops died and 11,721 were captured, making it the decisive defeat that led directly to the 1954 Geneva Conference and France's withdrawal from Indochina.
Estimates place military deaths in the First Indochina War at between 400,000 and 842,707 soldiers. Civilian deaths are estimated at between 125,000 and 400,000. Both sides committed war crimes, including killings of civilians, rape, and torture.
China recognized the Democratic Republic of Vietnam in January 1950 and supplied the Viet Minh with weapons, food, advisers, and training camps on Chinese soil. The United States recognized Bao Dai's State of Vietnam and began providing France with military aid starting in May 1950. By 1954, the United States was paying 80 percent of France's war costs, amounting to three million dollars per day in 1952.
The Geneva Accords of July 1954 recognized the 17th parallel north as a provisional military demarcation line, dividing Vietnam into two zones. The accords promised national elections in 1956 to determine a unified government. Neither the United States nor the State of Vietnam signed the accords. The Indochinese Federation was dissolved in December 1954, and the last French troops left Vietnam on the 28th of April 1956.
Ho Chi Minh declared Vietnamese independence on the 2nd of September 1945, the same day General Leclerc signed the Japanese armistice on behalf of France in Tokyo Bay. His declaration deliberately echoed the American Declaration of Independence, proclaiming that all men are created equal and endowed with unalienable rights. France moved to reassert colonial control within weeks, overthrowing the Viet Minh government in Saigon on the 23rd of September 1945.