Second Opium War

War from 1856 to 1860 between Britain and France against China's Qing dynasty, also known as the Arrow War. It began after Qing officials seized the British-registered ship Arrow and escalated into an Anglo-French advance on Beijing that burned the Old Summer Palace; the Convention of Peking of 24 October 1860 legalized the opium trade and ceded the Kowloon Peninsula to Britain.