When Europeans first began trading with other civilizations, they had a particular interest in Chinese goods. At first, they purchased Chinese porcelain, silk, and tea from Arab middle-men. As new technology and navigational skills helped them (especially the British) sail to China and trade with the Chinese directly, they found that the Chinese had little interest in what they had to offer. The Europeans were undeterred, however, so they looked for secondary markets to provide them with goods for which the Chinese would trade.
Polynesian relations, for example, were influenced largely by European commercial interest in China because the British needed goods found in the Pacific islands like sandlewood, pearls, and other exotics if they wanted to trade with China. The British so coveted Chinese tea, porcelain, and silk that they supported the Sulus and their complex pyramid of slavery scheme. For many years, the British acquired the goods they needed for Chinese trade with the Chinese from the Sulus and turned a blind eye to the slavery.
In time, the British discovered the the Chinese had an insatiable demand for silver because they resource rich Middle Kingdom was noticeably lacking in precious metals. Thus, silver, including some from the new world, became an important component of trade with China. The British used this commodity to supplement the goods they got from Polynesia and were able to conduct even more trade with China. In time, however, the British became reluctant to trade its precious metals, preferring to keep them at home to pay for mercenaries. They therefore began looking for a replacement.
They found it in opium. The British discovered that opium poppies grew well in their Indian colony and that the Chinese, especially low ranking members of the Chinese government, were quite fond of it. Since opium is an addictive substance, it created its own demand and allowed the British to take massive profits away from their Chinese trade. It also made their Indian colony profitably by giving it an important cash crop. In time, the Chinese government realized how much opium was destroying the Chinese economy and people and prohibited it. The British continued to import it, however, and China and Britain even fought a war, the Opium War, over the matter.
