First Opium War Begins; Start of China's Century of Humiliation

British merchants flooded China with opium from British India to address trade imbalances, creating approximately 12 million Chinese addicts by 1839. Emperor Daoguang appointed Commissioner Lin Zexu to stop the trade. Lin confiscated and destroyed over 20,000 chests of British opium at Guangzhou. Britain responded with military force. Superior British steamships and artillery defeated Qing forces by August 1842. China signed the Treaty of Nanjing, ceding Hong Kong Island to Britain, opening five treaty ports, paying indemnity, and granting British citizens immunity from Chinese law. The war exposed military and technological gaps between Qing China and Western powers.