This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
For most of the eighteenth century, the Qing court confined all Western trade to a single port, Guangzhou, under the Canton System. Foreign merchants were restricted to a strip of riverfront factories, barred from the walled city, and required to deal only through a licensed guild of Chinese merchants, the Cohong. British demand for tea, paid for chiefly in silver, produced a persistent trade deficit that British merchants closed by selling opium grown in India, in defiance of Qing prohibitions on the drug. In 1839 the emperor sent Lin Zexu to Canton as imperial commissioner. Lin blockaded the foreign factories, forced the surrender of British opium stocks, and destroyed roughly a thousand tons of it over twenty three days in June 1839, mixed with lime and salt and flushed to the sea. Britain treated the seizure as an attack on legitimate property and dispatched an expeditionary force. What followed was not a single campaign but two wars, seventeen years apart, that dismantled the Canton System entirely, opened new treaty ports, ceded Hong Kong, and wrote extraterritorial privilege into the peace terms that governed foreign residence in China for the next century.