Hát tuồng (also called hát bội, or simply tuồng) is a form of Vietnamese theatre. Hát tuồng is often referred to as classical 'Vietnamese opera' influenced by Chinese opera. It is believed that tuồng was imported from China around the 13th century when Vietnam was warring against the Mongol Yuan Dynasty. A famous actor named Lý Nguyên Cát (元吉) 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 tuồng had first had its beginnings in Vietnam in the royal court. Later on, it was adapted to travelling troupes who entertained commoners and peasants.