During the 19th and 20th centuries, foreign powers practiced imperialism in China through the imposition of unequal treaties, opening of treaty ports, and establishment of foreign concessions and leased territories. Starting with the 1842 Treaty of Nanking following the Qing dynasty's defeat by Britain in the First Opium War, various foreign powers, including Britain, France, the United States, Russia, Germany, and Japan, forced China to concede sovereignty and in turn gained territorial, economic, and legal privileges from China. Chinese historians widely include China's subjugation to foreign powers as part of the "century of humiliation."

Within treaty ports, foreign powers controlled enclaves, known as concessions; and gained leases on territories that operated as de facto colonies. Foreign citizens in these areas were granted extraterritoriality, exempting them from Chinese legal jurisdiction in favor of their own consular courts. Foreign powers also maintained their own police forces, military garrisons, and independent taxation systems. The Scramble for China in the late 19th century saw a rapid acceleration of this process, as major powers carved out exclusive spheres of influence across the country, a trend only partially checked by the United States' Open Door Policy.

The foreign presence led to major changes to China's economy and society. Major treaty ports, particularly in Shanghai and Tianjin, became hubs of industrialization, Western education, and international trade. They introduced Western manufacturing, banking systems, and cultural practices to the region. At the same time, the loss of national sovereignty, along with social and legal inequalities between foreigners and natives, sparked Chinese resistance to foreign imperialism resulting in events such as the Boxer Rebellion and May Fourth movement.

The framework of unequal treaties slowly began to diminish after the establishment of the Republic of China. Amidst the Second Sino-Japanese War and World War II in the 1940s, most foreign powers relinquished their extraterritorial rights and concessions. The Chinese Communist Party abolished the remaining concessions after prevailing in the Chinese Civil War, although the final vestiges of foreign imperialism remained until the handover of Hong Kong in 1997 and the handover of Macau in 1999. The legacy of this period has greatly shaped China and is reflected today in its foreign policy, national identity, and economy.

Terminology Unequal treaties The term "unequal treaties" refers to a series of one-sided agreements imposed upon China by foreign powers during the 19th and early 20th centuries. They were often signed following a Chinese capitulation from military defeats or threats. The terms specified obligations to be borne almost exclusively by China and included provisions such as ceding territory, paying reparations, opening treaty ports, relinquishing the right to control tariffs and imports, and granting extraterritoriality to foreign citizens. The earliest "unequal treaty" was the 1841 Convention of Chuenpi negotiations during the First Opium War, followed by the 1842 Treaty of Nanking.Dong Wang, China's Unequal Treaties: Narrating National History (Lanham, Md.: Lexington Books, 2005). Because the unequal treaties all guaranteed most favoured nation for the foreign powers, if any foreign power gained additional advantages in China, these were automatically extended to provide parity to the other foreign powers.

The term was popularized in the 1920s by Sun Yat-sen to describe the treaties that were signed during the "treaty century".Wang, Dong. (2005). China's Unequal Treaties: Narrating National History. Lanham, Maryland: Lexington Books. pp. 1–2. . With the rise of Chinese nationalism and anti-imperialism, both the Kuomintang (KMT) and the Chinese Communist Party (CCP) used the concept to characterize the loss of Chinese sovereignty that started in the 1840s. In assessing the term's usage in rhetorical discourse since the early 20th century, American historian Dong Wang notes that "while the phrase has long been widely used, it nevertheless lacks a clear and unambiguous meaning" and that there is "no agreement about the actual number of treaties signed between China and foreign countries that should be counted as unequal." However, within the scope of Chinese historiographical scholarship, the phrase has typically been defined to refer to the many cases in which China was effectively forced to pay large amounts of financial reparations, open up ports for trade, cede or lease territories, and make various other concessions of sovereignty to foreign spheres of influence, following military threats. The Chinese-American sinologist Immanuel Hsu states that the Chinese viewed the treaties they signed with the foreign powers as unequal "because they were not negotiated by nations treating each other as equals but were imposed on China after a war, and because they encroached upon China's sovereign rights ... which reduced her to semicolonial status".Hsu, Immanuel C. Y. (1970). The Rise of Modern China. New York: Oxford University Press. p. 239. .

Treaty ports

The treaty ports were designated Chinese cities that were opened to foreign trade and residence by the unequal treaties,William C. Johnstone, "International Relations: The Status of Foreign Concessions and Settlements in the Treaty Ports of China" American Political Science Review (1937) 31#5 pp. 942-948 online and lasted for approximately one hundred years. The Treaty of Nanking established the first treaty port, and the Second Opium War gave rise to a second group of treaty ports. At its peak, more than 80 treaty ports were established in China; initially by Britain, France, and the United States; but soon expanding to all of the major foreign powes by the end of the 19th century.

Concessions and leased territories The concessions were enclaves located in Chinese cities that were leased to, governed, and occupied foreign powers. In these concessions, foreigners were given the right to freely inhabit, trade, travel, and perform missionary evangelization. Some of these territories were directly leased by foreign powers, effectively removing them from the control of local governments and serving as de facto colonies.Peter Hibbard, The Bund Shanghai: China Faces West (Odyssey Illustrated Guides, 2007) A 1937 inventory of all the concessions along with a survey of their status done by W. C. Johnstone shows that, aside from the two international settlements at Shanghai and Xiamen, there were a total of 23 foreign concessions to 8 nations in 10 Chinese cities. In addition to the 23 formally established concessions, Britain, Japan, and the United States were granted rights to concessions in several additional treaty ports, but these rights were never exercised.William C. Johnstone (1937), p. 943–944.

In addition, territories were fully administered as colonies and had their sovereignty transferred to a foreign power in perpetuity. These include Portuguese Macau, and the areas of Hong Kong Island and Kowloon in British Hong Kong.

History 1839–1894: First unequal treaties

At the start of the 19th century, the Qing dynasty of China emerged from a golden age with a large population and territory. Under the Canton system, European powers were only allowed to conduct trade with China in Guangzhou. However, advances in transportation and communication, including steamships and railways, as well as intensified competition among major powers, began to drive foreign expansion into China.

First Opium War

In 1842, China was defeated by Britain in the First Opium War and signed its first unequal treaty, the Treaty of Nanjing. The treaty ceded Hong Kong Island to Britain in perpetuity and established the first five treaty ports,"British Subjects, with their families and establishments, shall be allowed to reside, for the purpose of carrying on their mercantile pursuits, without molestation or restraint at the cities and towns of Canton, Amoy, Foochow-fu, Ningpo and Shanghai", C. F. Fraser, The Status of the International Settlement at Shanghai,, Journal of Comparative Legislation and International Law, Vol. 21, No 1 (1939), p. 39. although there was no mention of establishing separate residential areas for foreigners in those ports to self-govern."However, not a single word on concession was found in the treaties, not to mention its establishment and government." Wanshu Cong, Frédéric Mégret, International Shanghai (1863–1931): Imperialism and private authority in the Global City, Leiden Journal of International Law (2021, 34), p. 918."The treaties that followed the Opium Wars only gave foreigners the right to reside in the newly-opened ports and said nothing about separate foreign settlements as such." P. K. Cassel, Grounds for Judgment, Oxford University Press (2012), p. 64.

Initially, the Daoguang Emperor of China still hoped to maintain the Canton system. The 1843 Treaty of the Bogue added extraterritorial rights that exempted British citizens from Chinese law in the treaty ports. The Chinese commissioner who negotiated the treaty reported to the emperor that the treaty ports would be strictly limited, stipulating that "the boundaries of an area should be designated which foreigners are not allowed to exceed" (), although this restriction was not clearly stated in the English-language version,"The Chinese version of the Bogue Treaty actually carried this wording, but the tone was not clearly reflected in the English version". Hanchao Hu, Beyond the Neon Lights - Everyday Shanghai in the Early Twentieth Century, University of California Press (1999), p. 31. and extraterritoriality continued to grow throughout the 1840s and 1850s.

In 1843, Captain George Balfour arrived in Shanghai as the first British consul. The local circuit intendant, Gong Muiju, had been trying to limit contacts between Chinese and foreigners following two violent incidents that occurred between them.Hanchao Hu (1999), p. 31.P. K. Cassel (2012), p. 64. As such, Balfour initially could not even find a house for the consulate. He finally chose a location north of Yangjing Creek and requested Gong to designate an area for their establishment. In 1845, Gong and Balfour established the Land Regulations () agreement to set the institutional basis for the British concession of Shanghai.

Arrival of France and the U.S.

In 1844, subsequent negotiations with the United States in the Treaty of Wanghia and France in the Treaty of Whampoa led to further concessions for these nations on the same terms as the British. Following the British example, Charles de Montigny established the French concession of Shanghai in 1849. The local circuit intendant, Lin Gui, proclaimed that a French settlement would be established on a strip of land between the Chinese city and the British settlement.