Chinese officials attempted to ban the importation of the highly addictive opium, but ultimately failed. The British declared war on China in a series of conflicts called the Opium Wars. Superior British military technology allowed them to claim victory and subject the Chinese to a series of unequal treaties.

Unequal Treaties
According to the 1842 Treaty of Nanjing, the Chinese were to:

1. Reimburse Britain for costs incurred fighting the Chinese
2. Open several ports to British trade
3. Provide Britain with complete control of Hong Kong
4. Grant extraterritoriality to British citizens living in China

Spheres of Influence
Eventually several European nations followed suit, forcing China to sign a series of unequal treaties. Extraterritoriality guaranteed that European citizens in China were only subject to the laws of their own nation and could only be tried by their own courts. Eventually western nations weary of governing foreign lands, established spheres of influence within China which guaranteed specific trading privileges to each nation within its respective sphere.

Eventually the United States demanded equal trading status within China, and rather than carve out its own sphere of influence, simply announced the Open Door Policy in 1899. This stated that all nations should have equal trading rights regardless of spheres of influence. While this may have prevented the further expansion of spheres of influences, it did little to restore Chinese sovereignty.

Chinese Reaction
Disgusted with the failed efforts of the Manchu Dynasty in ridding China of opium or foreign influence after the Opium Wars, Chinese citizens staged the Taiping Rebellion between 1850-1864. Already weakened, the Chinese officials turned to foreigners for help in putting down the rebellion, killing millions of Chinese in the process.

After the further insult of the Open Door Policy, Chinese nationalist staged the Boxer Rebellion in 1900. Viewed as a threat to the profits they enjoyed in their imperialist spheres of influence, foreign nations formed an international coalition that ended the uprising. With this victory, additional concessions were granted to foreign nations within China.

Finally, 5,000 years of dynastic rule in China came to an end in 1911. China tumbled into civil war as local warlords sought to control their locals, while nationalist leaders such as Sun Yixian sought to unify China. Civil war took hold of China after Sun’s death as Mao Zedong and his communist forces battled Sun's successor Jiang Jieshi for control of the country. In 1949, Mao established a communist government in mainland China while Jiang Jieshi fled to Taiwan and established a democratic government there.