What happen during the opium war?

The Opium Wars, also known as the Anglo-Chinese Wars, were the climax of trade disputes and diplomatic difficulties between China under the Qing Dynasty and the British Empire after China sought to restrict British opium traffickers. To most Chinese, a century of humiliation began with this war, in which Westerners sought to force a deadly drug on an Asian people, and then imposed an unequal treaty that pried open their country and annexed the island that became Hong Kong. The British struck upon an ingenious way to reduce a huge trade deficit. Their merchants bribed Chinese officials to allow entry of chests of opium from Britishruled India, though its importation had long been banned by imperial decree. Imports soared, and nearly every American company followed suit, acquiring "black dirt" in Turkey or as agents for Indian producers.

Commissioner Lin Tsehsu proceeded to Canton, seized vast stocks of opium and dumped the chests in the sea. This, plus a melee in which drunken sailors killed a Chinese villager, furnished the spark for the Opium War, initiated by Lord Palmerston, the British Prime Minister, and waged with determination to obtain full compensation for the opium. The Celestial Empire was humbled, forced to open five ports to foreign traders and to permit a British colony at Hong Kong. The Opium War was no doubt the event that opened China's doors to the outside world. Before 1842, China was closed and self isolated.