The Opium Wars.

the opium wars was a preparation made from the juice of poppy seedpods, and used to produce heroin. What happened during the Opium wars was that the Chines did not want to trade with the British any more because the British were selling a harm full drug to the Chines for tea. So the British did not like this so they fought the Chines. The British won the war because the British had advanced technology and strong army's but most importantly strong ships that the Chines could not stand a chance to there own.