https://www.britannica.com/topic/Opium-Wars

Colombia and Peru have nothing on these guys!

Not only did the wealth come from the slave trade, it also came from drug dealing opium which is known today as heroin and in the medicinal field morphine for severe pain. Foreign traders (primarily British) had been illegally exporting opium mainly from India to China since the 18th century, but that trade grew dramatically from about 1820. The resulting widespread addiction in China was causing serious social and economic disruption there. The Opium Wars arose from China’s attempts to suppress the opium addiction of its people.