Britain and France Declare War on China

Britain and France formally declared war on China on March 3, 1857, escalating a series of diplomatic incidents and trade disputes into the Second Opium War. The immediate trigger was the Arrow Incident, in which Chinese officials boarded a Hong Kong-registered ship and arrested its crew, which Britain claimed was an insult to its flag. France joined after the execution of a French missionary in Guangxi province. The combined expeditionary force eventually reached Beijing in 1860, looting and burning the Old Summer Palace, one of the greatest architectural complexes in East Asia, in retaliation for the torture and killing of British and French envoys. The resulting Treaty of Tientsin opened ten new ports to foreign trade, legalized the opium trade that China had tried to ban, permitted Christian missionaries to operate freely in the interior, and installed permanent Western ambassadors in Beijing. The treaty system created what Chinese historians call the 'Century of Humiliation.'