The First Opium War, also known as the Opium War or the Anglo-Chinese War, was a series of military engagements fought between the United Kingdom and the Qing dynasty of China over their conflicting viewpoints on diplomatic relations, trade, and the administration of justice in China.
In the 17th and 18th centuries, the demand for Chinese goods (particularly silk, porcelain, and tea) in Europe created a trade imbalance between Qing Imperial China and Great Britain. European silver flowed into China through the Canton System, which confined incoming foreign trade to the southern port city of Canton. To counter this imbalance, the British East India Company began to auction opium grown in India to independent foreign traders in exchange for silver, and in doing so strengthened its trading influence in Asia. This opium was transported to the Chinese coast, where local middlemen made massive profits selling the drug inside China. The influx of narcotics reversed the Chinese trade surplus, drained the economy of silver, and increased the numbers of opium addicts inside the country, outcomes that worried Chinese officials. (more on Wiki HERE)