First Opium War between China and the United Kingdom
In the early 19th century, opium smuggling in China was a real political and economic problem. In 1838, Emperor Daoguang ordered the destruction of stocks of opium held by traffickers (mainly British) in Canton, the heart of the trade and only Chinese city open to foreigners. The British retaliated by sending out a war fleet. The first Opium War ended, in 1842, with China's defeat and the signing of the Treaty of Nanking, which forced the Chinese to cede the island of Hong Kong, and accept greater economic openness.