Britain and France Declare War on China

Britain went to war with China over a flag. The immediate trigger for the Second Opium War was the Arrow Incident of October 1856, in which Chinese officials boarded a Hong Kong-registered ship called the Arrow and hauled down its British flag while arresting suspected pirates. The British consul in Canton insisted the flag had been disrespected; China maintained the ship's British registration had expired. On March 3, 1857, Britain and France formally declared war, launching a conflict that would force China to open further to Western trade and legalize the opium that was destroying millions of Chinese lives. The First Opium War (1839-1842) had already humiliated China, forcing the cession of Hong Kong and the opening of five treaty ports. But Western merchants wanted more access to the Chinese interior, and the opium trade, technically still illegal under Chinese law despite the treaty system, continued to expand. British merchants were shipping over 60,000 chests of Indian opium to China annually by the 1850s. France joined the British campaign after the execution of a French missionary, Auguste Chapdelaine, in Guangxi province in early 1856. The combined Anglo-French force was formidable but slow to mobilize — the Indian Rebellion of 1857 diverted British troops for over a year. Operations in China began in earnest in late 1857 with the capture of Canton, where the allied forces installed a puppet administration. The war escalated dramatically in 1860 when Anglo-French troops marched on Beijing after Chinese forces violated a truce and tortured captured negotiators, killing twenty. Lord Elgin ordered the burning of the Old Summer Palace, the Yuanmingyuan, as retaliation — destroying one of the greatest architectural complexes in world history, with an estimated 200 buildings and priceless art collections reduced to ash over three days. The Treaty of Tientsin and the Convention of Peking forced China to open eleven more ports, legalize opium imports, permit foreign diplomats in Beijing, and cede Kowloon to Britain. The Second Opium War deepened China's "Century of Humiliation" and fed the internal pressures that would eventually topple the Qing Dynasty.