Drama was introduced to China in the 13th century by the Mongols, and reached a golden age during the Yuan Dynasty from 1200-1368 when many plays were written. Chinese drama traditionally emphasized moral lessons and used symbolic props rather than realistic sets, with actors trained from a young age in speech, movement, and roles. Various forms of Chinese theater developed over time, with Peking Opera becoming dominant in the 19th century and some turn to realism after the early 20th century.