The Opium War, also known as the First Sino-British War, took place between June 1840 and August 1842. The war was triggered by the Qing government’s ban on the British opium trade to China. As a result of the Qing army’ defeat, the government was forced to sign an unequal treaty. This war is regarded as the beginning of China’s modern history.

As the first country to complete the Industrial Revolution in the first half of the nineteenth century, Britain witnessed a tremendous growth in productivity and urgently sought overseas markets. The British merchant fleet, equipped with cannons and loaded with cheap goods, sailed the oceans under the banner of “free trade” and forced many countries to open their doors to trade.

Meanwhile, China maintained a closed-door policy, with only Guangzhou open to foreign trade. The Qing empire (1644–1911), regarding itself as the Superior Heavenly Kingdom, had little knowledge of other nations or what was happening in the outside world. In 1793, the Qianlong emperor (r. 1735–1795) wrote to the King of Britain that China lacked for nothing and it was merely charitable of China to do business with the British. Two years after the eruption of the Opium War, the Daoguang emperor (r. 1820–1850), who still had no idea where Britain was located, asked his courtiers whether a land route could be taken from England to Xinjiang.

Before the Opium War, Britain purchased more goods from China than China did from Britain. In order to reverse the trade deficit, the British started smuggling opium and selling it in China for exorbitant profits. Many Chinese people became addicts and the outflow of huge amounts of silver was not only detrimental to the nation’s finances but to people’s lives as well.

At the end of 1838, the Daoguang emperor, who had been disturbed by the opium issue, was determined to ban the trade. He appointed Lin Zexu (1785–1850) as imperial commissioner to Guangdong. Adopting strict measures in Guangzhou, Lin not only investigated and penalized Chinese opium traders, but targeted foreign merchants. He compelled the British to surrender 20,283 chests of opium (over one million kilograms) and had them destroyed at Humen between June 3 and June 25, 1839.

Considering that the destruction of opium would only affect the interests of the British merchant fleet, Lin Zexu did not expect that the British government would be infuriated. In June 1840, the British expeditionary force arrived in Guangdong. With a small number of troops blockading the mouth of the Pearl River, the main force seized Dinghai in Zhejiang in July and moved north. In August, the army’s arrival at the port of Tianjin shocked the Qing government in nearby Beijing. The British army presented Prime Minister Palmerston’s (1784–1865) diplomatic note, the major content of which contained indictments against Lin Zexu’s suppression of opium; the note also required China to cede territories and to indemnify Britain for the military expenditure and confiscated opium. Mistaking the intention of the British for merely an indictment for the prohibition of opium, the Daoguang emperor dismissed Lin Zebu.

Britain expected far more than the dismissal of Lin Zexu, however. On January 7, 1841, the British troops raided and occupied both Dajiao Fort and Shajiao Fort in Humen. Relying on modern weapons, the British troops advanced north and made a clean sweep from Guangzhou to Nanjing, capturing the cities of Xiamen, Dinghai, Zhenhai, Zhapu, Wusong, and Zhenjiang along the east coast.

Having suffered one defeat after another, the Qing government was forced to negotiate peace with Britain. On August 29, 1842, the Qing representatives signed the unequal Treaty of Nanking with the British representatives, which ended the first Opium War.

According to the Treaty of Nanking, China’s first unequal treaty signed under foreign coercion: Hong Kong Island was ceded to Britain; China paid Britain reparations of twenty-one million silver dollars; five ports of Guangzhou, Fuzhou, Xiamen, Ningbo, and Shanghai were opened for trade; tariffs on British imports and exports in China were to be decided by both governments; British nationals were given extraterritorial rights in all disputes in China; and other concessions. In 1843, Britain forced the Qing government to sign the Treaty of the Bogue (Humen) which granted most-favored nation status to Britain and gave British citizens the right of extraterritoriality. In the next few years, the United States, France, Belgium, Sweden, and other powers followed suit and forced the Qing government to enter into similar treaties, which severely damaged China’s sovereignty.

The Opium War fundamentally changed the nature of Chinese society. It destroyed China’s sovereignty in territory, jurisdiction, and tariffs; it tore apart China’s self-sufficient economy, and dragged her into the world market. In the meantime, the Chinese people began to pay attention to Western thought and culture, and thus commenced the eastward spread of Western learning in the late Qing dynasty.