Hoa Hao :Phat Giao Hoa Hao, Vietnamese Buddhist religious movement that was formed in 1939 by the Buddhist reformer Huynh Phu So. The Hoa Hao, along with the syncretic religious group Cao Dai, was one of the first groups to initiate armed hostilities against the French and later the Japanese colonialists. Based in the prosperous Mekong River delta area of southern Vietnam, where its adherents were mostly peasants, tenants, and rural workers, the Hoa Hao grew rapidly during the Japanese occupation in World War II. After the war, it continued as an independent force in Vietnamese politics, opposing both the French colonialists and the Viet Minh nationalist movement of Ho Chi Minh.