The First Opium War between the United Kingdom and China broke out in 1839 and ended in 1842. This conflict was fought over the Qing dynasty’s refusal to continue trade with Great Britain and to allow the importation of opium, a drug largely produced by the British East India Company in India.
The root cause of the war can be traced back to the unequal treaties of the 18th century such as the Treaty of Nanking and the Treaty of Tientsin, which required China to pay indemnities to Great Britain for the damage caused by the British during the Opium War. Despite the restrictions imposed by these treaties, the British were able to continue their opium trade through the illegal smuggling of the drug into China.
By the 1830s, Chinese demand for opium had soared and British merchants and private traders had increased their presence in Chinese ports. As a consequence, the Qing dynasty sought to tighten its control over the opium trade and issued an edict in March 1839 that prohibited the opium trade and ordered it to be confiscated. This led to a confrontation between the British and Chinese forces in Canton (Guangzhou) which eventually sparked the outbreak of war.
During the war, the British forces entered Chinese coastal cities and inflicted major defeats on the Chinese. Eventually, the Treaty of Nanjing was signed on 29 August 1842, ceding Hong Kong to Britain and allowing the importing of opium into China. This treaty also stipulated that ports across China would be opened to British merchants and allowed them most-favored-nation status.
Despite being militarily weaker than the British, the Qing dynasty had refused to negotiate a settlement over the opium trade up until the start of the war. The Qing dynasty’s refusal to capitulate forced the British to resort to violence, ultimately resulting in the outbreak of the First Opium War. The Treaty of Nanjing did not settle the opium issue and led to an increase in opium imports into China, leading to the Second Opium War in 1856.