Opium Wars, 1839-42 and 1856-60, two wars between China and Western countries. The first was between Great Britain and China. Early in the 19th cent., British merchants began smuggling opium into China in order to balance their purchases of tea for export to Britain. In 1839, China enforced its prohibitions on the importation of opium by destroying at Guangzhou (Canton) a large quantity of opium confiscated from British merchants. Great Britain, which had been looking to end China's restrictions on foreign trade, responded by sending gunboats to attack several Chinese coastal cities. China, unable to withstand modern arms, was defeated and forced to sign the Treaty of Nanjing (1842) and the British Supplementary Treaty of the Bogue (1843). These provided that the ports of Guangzhou, Jinmen, Fuzhou, Ningbo, and Shanghai should be open to British trade and residence; in addition Hong Kong was ceded to the British. Within a few years other Western powers signed similar treaties with China and received commercial and residential privileges, and the Western domination of China's treaty ports began. In 1856 a second war broke out following an allegedly illegal Chinese search of a British-registered ship, the Arrow, in Guangzhou. British and French troops took Guangzhou and Tianjin and compelled the Chinese to accept the treaties of Tianjin (1858), to which France, Russia, and the United States were also party. China agreed to open 11 more ports, permit foreign legations in Beijing, sanction Christian missionary activity, and legalize the import of opium. China's subsequent attempt to block the entry of diplomats into Beijing as well as Britain's determination to enforce the new treaty terms led to a renewal of the war in 1859. This time the British and French occupied Beijing and burned the imperial summer palace (Yuan ming yuan). The Beijing conventions of 1860, by which China was forced to reaffirm the terms of the Treaty of Tianjin and make additional concessions, concluded the hostilities.

Two trading wars of the mid-19th century in China. The first (1839–42 was between China and Britain, and the second (1856–60; also called the Arrow War or Anglo-French War) was between China and a British-French alliance. Trade developed between China and Western countries from the late 16th century. The Chinese, accustomed to tributary relationships with others, required that Westerners pay for Chinese goods with silver currency. To offset a growing negative flow of silver at home, the British created a market for opium in China and began importing it there illegally. As demand for opium grew, China tried to stop the practice, and hostilities broke out. Britain quickly triumphed, and the resultant Treaty of Nanjing (Nanking;1842; the first of a series of unequal treaties between China and Western countries and, eventually, Japan) was a blow to China. The outbreak of the second war resulted in the Treaty of Tianjin (Tientsin; 1858), which required further Chinese concessions. When China refused to sign subsequent treaties, Beijing (Peking) was captured and the emperor's summer palace burned. The overall result of these conflicts was to weaken the Chinese imperial system, greatly expand Western influence in China, and pave the way for such uprisings as the Taiping and Boxer rebellions. Seealso Canton system; British East India Company; Lin Zexu.

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