What events caused the First Opium War between Britain and China?

The First Opium War (1839–1842) was primarily caused by deep-seated diplomatic tensions and China’s efforts to suppress the illegal opium trade, which had caused widespread addiction and severe economic disruption within the country.123

Key factors leading to the conflict included:

• Trade Imbalance: Britain faced a chronic trade deficit with China, as there was high demand for Chinese tea, silk, and porcelain but little demand for British goods. To balance this, British merchants—supported by the East India Company—smuggled opium from India into China, causing a massive outflow of Chinese silver.234
• Restrictive Trade Policies: The Canton system confined all foreign trade to the port of Guangzhou and subjected merchants to strict regulations, which British traders increasingly resented.25
• Enforcement Actions: In 1839, the Daoguang emperor appointed Lin Zexu as imperial commissioner to end the smuggling. Lin confiscated and destroyed over 20,000 chests of opium, representing a significant financial loss for British merchants.236
• Legal Disputes: Tensions escalated in July 1839 after British sailors killed a Chinese villager. Britain refused to surrender the accused to the Chinese legal system, which they viewed as barbaric.24

Hostilities formally began in late 1839 when British warships broke a Chinese blockade, leading to a conflict that ultimately forced China to sign the Treaty of Nanjing.234