H?t tu?ng (also called h?t b?i, or simply tu?ng) is a form of Vietnamese theatre. H?t tu?ng is often referred to as classical 'Vietnamese opera' influenced by Chinese opera. It is believed that tu?ng was imported from China around the 13th century when Vietnam was warring against the Mongol Yuan Dynasty. A famous actor named L? Nguy?n C?t (じ) was imprisoned by the Vietnamese. The imperial court asked him to spread his knowledge of Chinese theatre to the children of the elite, thus explaining how tu?ng had first had its beginnings in Vietnam in the royal court. Later on, it was adapted to travelling troupes who entertained commoners and peasants.