In the nineteenth century, after the period of the Napoleonic Wars, Europe returned with its strong commercial rhythm, the East Indies were the main destination markets for European products at the time. China and India, for having such a large population, were the most attractive markets for the various European products, mainly the English, since England was the greatest power at the time and was already on the way to the second phase of the Revolution Industrial.
Although India had a market quite open to foreign products, China was quite the opposite: it had no interest in almost any European product, it closed its economy, in addition to calling foreigners “barbarians”. The only product that aroused Chinese interest was opium, a drug extracted from the poppy that causes chemical dependency. Even though it was illegal, the use of opium in China became widespread in 1834, generating great profits for England.
In 1839, the Chinese Emperor Daoguang established a confiscation policy in Chinese ports, one of his envoys. he was murdered by opium-drunk British sailors, which led to the expulsion of all English from the City. In addition, the Chinese government confiscated and destroyed some 20,000 cases of opium in British warehouses, prompting England to declare war on China.
With enormous military advantages and unquestionable technological superiority, the British won easily the Chinese forces, bombing Nanjing and threatening ground communications with the capital, Beijing. This forced China to sign the Treaty of Nanjing, in 1842, in which China guaranteed the opening of five more ports to English rule, the payment of compensation for the war in addition to handing over the island of Hong Kong.
Even with a completely favorable agreement, the British could not, with great success, reach the desired profit, as the trade did not progress as quickly as intended.
16th to 19th century - wars - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/guerras/primeira-guerra-opio.htm