The First Opium War or the First Anglo-Chinese War was fought between Great Britain and the Qing Empire in China from 1839 to 1842 with the aim of forcing China to import British opium. It is often seen as the beginning of European imperial hegemony towards China. The conflict began a long history of Chinese suspicion of Western society that still has remnants today.
In the 19th century the British were heavily involved in trafficking opium distilled from the juice of poppy seeds growing in fields controlled by the British Raj. The market was China. The Chinese tried to stop the trade and this led to the Opium War of 1839-1842.
The Chinese economy was poor. The emperors had lost control. The Mandarin classes were corrupt as was the untrustworthy army. The East India Company needed the Chinese market for the money it made and because they could gather taxes if their Indian opium growers were profitable. The answer to raising taxes was in ginger and opium.
A district report claimed that "the best opium is obtained in that portion situated north and east of the Simla range and the finest ginger in the southern Thakooraees… The cultivation of these important articles of export would be increased and additional employment would be found for the inhabitants of all classes in the opium fields and this pernicious but useful drug would become a monopoly in our hands".
In the spring of 1839 the Chinese authorities at Canton seized the opium and set fire to it. It took time for the news to reach London. In 1840 British forces moved towards Tientsin. In January 1841 they took Hong Kong and kept it until the Japanese occupation during the Second World War.
The Chinese were forced to negotiate. But the fighting continued. The British took city after city including Cha-p'u and Shanghai and very nearly Nanking. The Chinese offered a three million dollar ransom to the British if they would not bombard Nanking. The negotiations were protracted because it took days to translate Chinese documents into English and then English documents in Chinese.
On 29 August 1842 the Opium War ended with the Treaty of Nanking. The Chinese paid the British a multimillion dollar indemnity, ceded Hong Kong and opened five treaty ports to traders: Canton (which had been open), Foochow, Nangpo, Amoy, and Shanghai.