"Once Upon a Time in China" is a Hong Kong martial arts film series that began in 1991. The story follows the legendary Chinese folk hero Wong Fei-hung, portrayed by Jet Li, as he defends traditional Chinese values against foreign influences and local corruption during the late 19th century. The film combines action, drama, and cultural themes, showcasing various martial arts styles. The series is known for its impressive choreography and historical context, highlighting the struggles of the Chinese people during a time of upheaval. It has gained popularity for its engaging storytelling and has influenced many subsequent martial arts films.