In the 19th century, British companies sold opium to China to balance their trade deficits. When China banned the drug, Britain started a war in 1840. Dr. Qiao explains why Britain started the Opium War and how it marked the beginning of modern Chinese history.

On-camera reporter: Qiao Liang 

Script writer: Qiao Liang

Video editor: Lu Chang

Filmed by: Danzeng Jiancuo

Chief editor: Wang Xin

Producer: Wen Yaru

Director: Zhang Shilei 

Supervisor: Fan Yun