Before considering the Zen-Pure Land union as introduced to Vietnam through the Thảo Đường school, let us survey the Vietnamese Buddhist scene from the Ddinh (969-981) to Tran (1225-1400) dynasties when Buddhism developed from a national religion to a nationalist religion before merging with aspects of Taoist and Confucian beliefs characteristic of the unification of the three religions following the decline of Buddhist influence in the Late Trän dynasty.