Buddhism was brought to this region in about the 5th century mainly by Indian merchants and monks on their way to China. In later centuries Chinese influence became dominant in Vietnam and the country adopted Chinese forms of Buddhism. After the 1870’s when the French conquered the country, Buddhism was persecuted because it was associated with Vietnamese identity.
After the Second World War the communists in north Vietnam suppressed Buddhism completely, while Buddhists in the south were brutally persecuted by the Catholic regime of Ngo Dinh Diem. Today the whole country is communist and Buddhism continues to suffer under numerous restrictions. Many Vietnamese refugees in America, Australia and Europe have managed to continue their religious life.
Buddhism and Zen in Vietnam, Thich Thien-An, 1975.