Skip to content

The Opium Wars and the Treaties That Followed Them

Britain fought two wars to keep an illegal drug trade open in China. The commercial mechanics, the Qing prohibition and the treaty terms, from the archives.

By Published 6 min read

Reign Creative LLC makes World History Timeline Sim, which this article links to, so we have a commercial interest in it. How we write and check articles.

Key takeaways

  • China prohibited opium completely in 1796, according to The National Archives, and British merchants went on smuggling it in at volumes the archive puts at over 1,000 tonnes a year by the early nineteenth century.
  • The trade existed to solve a British balance-of-payments problem: MIT's Visualizing Cultures records that by 1800 the East India Company was buying 23 million pounds of tea a year at a cost of 3.6 million pounds of silver.
  • Opium imports rose from about 4,000 chests in 1790 to roughly 10,000 in the early 1820s and about 40,000 in 1839, on the figures given by Visualizing Cultures.
  • Commissioner Lin Zexu's 1839 letter to Queen Victoria, held in Fordham University's sourcebook, makes the argument in one line: Britain banned the drug at home and exported it abroad.
  • The Treaty of Nanking, held at The National Archives as FO 93/23/1b, ceded Hong Kong Island in Article 3, opened British trade with any Chinese merchant in Article 5, and imposed payment for the opium the Qing state had destroyed.
  • A second war followed from 1856 to 1860, and further agreements in 1898 leased the New Territories for 99 years, a term that set the 1997 handover date.

The Opium Wars were fought to keep an illegal drug trade open. China had prohibited opium outright in 1796, according to The National Archives; British merchants went on smuggling it in from British-controlled India at volumes the archive puts at over 1,000 tonnes a year by the early nineteenth century; and when Qing officials enforced their own law in 1839 by seizing and destroying stock, Britain went to war and won. The settlement that followed ceded Hong Kong Island, opened Chinese ports on British terms and required China to pay for the opium its own government had confiscated. None of that is a controversial reconstruction — the treaty is a catalogued document in a national archive.

The trade imbalance that created the trade

Start with the commercial mechanics, because the drug trade was a solution to a problem, and the problem came first.

Britain wanted Chinese tea in enormous quantity. MIT's Visualizing Cultures project records that by 1800 the East India Company was buying 23 million pounds of tea a year "at a cost of 3.6 million pounds of silver". The difficulty was that Britain produced little the Chinese market wanted in exchange, so payment flowed out in bullion. Opium grown in British-controlled India reversed that flow.

The scale of the reversal is visible in the import figures Visualizing Cultures gives: about 4,000 chests in 1790, around 10,000 in the early 1820s, and roughly 40,000 by 1839. By the 1830s the project estimates some 10 million Chinese consumers, of whom around 2 million were addicted. The National Archives summarises the same process plainly: Britain "started growing opium in its Indian colonies and exporting it to China, where it spread through the population".

This is the part that gets softened in older teaching. The trade was not an unfortunate side effect of commerce. It was a deliberate commercial strategy, pursued after prohibition, by merchants and an imperial administration that knew it was illegal in the destination country.

The Qing prohibition, and the 1839 confrontation

China banned opium in 1796. Enforcement was inconsistent for decades, partly because enforcement is difficult against a sea-borne smuggling network and partly because officials at several levels were implicated in it. Neither fact changes the legal position.

In 1839 the Daoguang emperor appointed Lin Zexu as imperial commissioner with authority to suppress the trade, and Lin arrived at Canton in March of that year. His letter to Queen Victoria, preserved in Fordham University's sourcebook, sets out the Qing case in terms a modern reader has no difficulty following. On Britain's domestic prohibition: "Since then you do not permit it to injure your own country, you ought not to have the injurious drug transferred to another country." On the commercial relationship: "Your honorable nation takes away the products of our central land, and not only do you thereby obtain food and support for yourselves, but moreover, by re-selling these products to other countries you reap a threefold profit."

Lin confiscated and destroyed the opium stocks held at Canton. The National Archives dates the outbreak of the first war to 4 September 1839. Reading Lin's letter before reading any modern summary is instructive, and it is a good practical example of the difference between primary and secondary sources: the argument in the document is not the argument later historiography put in his mouth.

The treaties, and why the adjective is accurate

The first war ended in 1842 with the Treaty of Nanking, held at The National Archives under catalogue reference FO 93/23/1b. Its Article 3 granted Hong Kong Island to Britain. Its Article 5 allowed British subjects to trade with any merchants in China, which dismantled the licensed monopoly through which Canton trade had been channelled. China was required to pay damages for the opium its officials had destroyed, and additional ports were opened.

A second war followed from 1856 to 1860, bringing further territorial and commercial concessions including the addition of Kowloon to the Hong Kong colony. In 1898 a convention leased the New Territories for 99 years, a term whose arithmetic set the date of the handover on 1 July 1997.

"Unequal treaties" is a description of structure, not a slogan. The obligations ran one way: indemnities, ceded territory, tariffs fixed by agreement rather than by Chinese law, and legal privileges for foreign nationals on Chinese soil. They were signed after military defeat by a state that had no realistic option to refuse. That is what the phrase names.

The "century of humiliation", held at arm's length

The period from 1839 onward is described in Chinese public discourse as a century of humiliation, and the phrase does two jobs at once.

It describes something documented: a sustained sequence of military defeats, imposed treaties, territorial losses and foreign privilege inside Chinese territory. It is also an organising frame used in present-day political argument, both domestically and internationally, and it selects and emphasises accordingly.

A careful account states both, attributes both, and refuses two opposite temptations: dismissing the framing because it is politically useful, or adopting it wholesale as though the nineteenth century contained nothing else. The Qing state of this period was simultaneously fighting the enormous internal conflicts covered in our article on China's deadliest rebellions, which is part of why its capacity to resist was what it was. Qing officials were neither uniformly helpless nor uniquely corrupt; they were administrators of a very large state under simultaneous internal and external pressure, and some of them, Lin among them, acted decisively on the law as it stood.

Visualizing Cultures notes that conventional Chinese historiography dates the modern period from the end of the first war in 1842. That is itself a periodisation decision with consequences, of the kind our guide to how historians date events unpacks — and a reminder that where a period is cut determines what looks like a cause. The same problem sits underneath the long argument over what caused the Bronze Age collapse, where the chosen start and end dates do a great deal of unacknowledged work.

Where this sits on a world timeline

World History Timeline Sim is our own app, built by Reign Creative, and the nineteenth-century East Asian cluster is one of the places where a chronology earns its keep.

The app holds First Opium War and Second Opium War entries among its 209 war records and a Qing Dynasty record among its 239 civilizations, which puts the wars next to the Taiping Rebellion, the treaty-port expansion and the later reform movements rather than in a self-contained British-empire narrative. Seeing them adjacent is the point: the pressure on the Qing state was internal and external at the same time, and a single-strand telling of either story misleads.

The app is a learning and exploration tool. Its content carries no citations and no external review, and it does not replace teachers, scholarly books, archives or the treaty texts themselves — which, in this case, you can go and look at in a national archive's catalogue. Related material sits in the major historical events hub, alongside our introduction to the Silk Road for the much older trade networks this period displaced, and the wider set of education and brain training articles.

What to take away

The cause was enforcement of a drug ban, and the objective was forced market access. Keep the two separate: the first is the trigger, the second is what the victory was used for.

The terms are documented, not inferred. Articles 3 and 5 of the Treaty of Nanking, in a catalogued archival file, say what the settlement did.

Name the coercion, and keep the framing attributed. The trade was deliberate and illegal in China; the "century of humiliation" describes real events and is also a live political frame, and a good account says both.

Good to know

Frequently asked questions

What were the Opium Wars about?
Keeping an illegal drug trade open. China had prohibited opium in 1796, British merchants smuggled it in at scale from British-controlled India, and when the Qing state enforced its own law by destroying confiscated stock in 1839, Britain went to war. The wider British objective was to force open Chinese ports and end the restricted Canton trading system, but the immediate cause was the enforcement of a drug prohibition.
Why did Britain sell opium to China at all?
To fix a balance-of-payments problem. Britain bought enormous quantities of Chinese tea for silver — by 1800 the East India Company was buying 23 million pounds of tea a year at a cost of 3.6 million pounds of silver, on Visualizing Cultures' figures — and had little the Chinese market wanted in exchange. Opium grown in British India reversed the flow of silver.
What did the Treaty of Nanking actually impose?
The National Archives holds the treaty as FO 93/23/1b. Article 3 granted Hong Kong Island to Britain. Article 5 allowed British subjects to trade with any merchants in China, dismantling the licensed monopoly system at Canton. China was also required to pay for the opium its officials had destroyed, and further ports were opened to British trade.
Why are these called unequal treaties?
Because the obligations ran in one direction. The settlements imposed indemnities, territorial cessions, fixed tariffs and extraterritorial legal privileges on China without reciprocal concessions, and they were signed under military defeat. The phrase is a description of the terms rather than a rhetorical flourish, though its later use in Chinese political argument gives it an additional life that should be noted separately.
When did the wars happen?
The first ran from 1839 to 1842; The National Archives dates its outbreak to 4 September 1839. The second ran from 1856 to 1860. MIT's Visualizing Cultures notes that conventional Chinese historiography dates the beginning of the modern period from the end of the first war in 1842, which is itself a periodisation choice worth noticing.

Sources

  1. Hong Kong and the Opium Wars — education resource (opens in a new tab)The National Archives (United Kingdom) — accessed
  2. The Opium Trade — Visualizing Cultures (opens in a new tab)Massachusetts Institute of Technology — accessed
  3. Commissioner Lin: Letter to Queen Victoria, 1839 (opens in a new tab)Fordham University, Internet Modern History Sourcebook — accessed
  4. USC U.S.-China Institute (opens in a new tab)University of Southern California — accessed

About the author

— The independent app studio that builds the apps covered on this site and publishes every article here. On Google Play it publishes as Reign Collective Apps.

We use AI tools to help research, draft and edit our articles. Each article lists the sources its factual claims rely on, and details about our apps come from their live Google Play listings. No article on this site has been reviewed by an independent expert unless the reviewer is named on it.

Spotted an error? Tell us — how corrections are handled is set out in our editorial policy.

Keep reading