Choson, in what is now northwestern Korea and southern Northeast China; it was conquered by the Han Chinese in 108 BC. Thereafter the Chinese set up military outposts in Korea that helped spread Chinese culture and civilization. The first of the three main Korean kingdoms to come in contact with the spreading Chinese influence was Koguryo, which emerged in the 1st century BC in the north. Paekche in the southwest and Shilla in the southeast, which emerged in the 3rd and the 4th century AD, respectively, had contact with China as well. To a degree these kingdoms accepted Buddhism, Confucianism, and most importantly, Chinese characters as a means of communication and education. Paekche and Shilla also had contact with Japan, along with a fourth, smaller kingdom called Kaya, located on the central southern coast. Paekche and Kaya had political and military alliances with Japan; Paekche would later call upon Japan during a war with Shilla, but the aid came too late for Paekche to survive. Kaya and Japan had particularly close ties, and for many years Japanese historians depicted Kaya as a Japanese-dominated kingdom. Korean scholars have long rejected that view, and most modern historians are divided as to which kingdom, if either, dominated the other. At the time, both the Korean Peninsula and the Japanese islands were divided among several kingdoms and fiefdoms.

Koguryo was initially the most powerful kingdom, controlling most of the peninsula and Manchuria by the 5th century. In the mid-6th century, Shilla conquered Kaya and seized the area around what is now Seoul in the Han River valley, while inflicting steady territorial losses on Koguryo and Paekche. By 688 Shilla, in alliance with the Chinese Tang (T'ang) dynasty, had conquered first Paekche and then Koguryo, creating the first unified Korean state.

Buddhism, which appeared on the peninsula during the 4th century and grew to a powerful force by the 6th century, inspired much of Shilla's intellectual and artistic life. Chinese culture, written language, and political institutions were also extremely influential. Shilla's native culture, however, was the basis for Korean development in this period. By the 10th century a distinctively Korean state was firmly rooted, and despite many later changes and vicissitudes, this Korean polity has endured until modern times.

KORYO PERIOD (918-1392)  
During the 9th century Shilla's monarchy and governing institutions declined, and regional leaders gained strength at the expense of the central government. From 890 to 935 the three main kingdoms reemerged on the peninsula. This time the northern state, Koryo (the name, which is derived from Koguryo, is reflected in the modern Western name, Korea), accomplished unification. Founded in 918 by an astute warrior and statesman named Wang Kon, Koryo brought Korea's regional leaders under a single central authority and extended the frontiers of the country north to the Yalu River. Here Koryo came into conflict with the Manchurian Khitan (Liao) dynasty, fighting wars from 993 to 1018. Peace was achieved in 1022, with Koryo regaining all the territory contested by the Manchurian Khitan dynasty.

The full flowering of Koryo culture took place in the 1100s. It was marked by a stable central government, influenced by Chinese political institutions and methods; a vigorous Buddhist faith that inspired many achievements in scholarship and art; and a particularly distinctive ceramics industry that produced exquisite celadon-stoneware with a gray-green, iron-pigmented glaze-which are still appreciated today. In the early 12th century, however, stability began to give way. Powerful aristocratic families contended with the throne for political control, and the Manchurian Jin (Chin) dynasty added pressure from outside, provoking divisive responses from a now uncertain leadership. In 1170 a group of military officers, who felt civilian officials had too much power, threw out the officials and turned the kings into figureheads controlled by the officers, thus beginning a period of internal strife. The Mongols invaded Korea in 1231, launching a series of wars that ended with their conquest of Koryo in 1259. Under the Mongols the Korean kings recovered their power from the military. Koryo was able to drive out the Mongols in 1356, but in the long run it was unable to restore its institutions or contain the new political forces it encountered. In 1392, after nearly 500 years, the state came to an end.

THE CHOSON (YI) DYNASTY (1392-1910)
During the 14th century Korea came under the influence of Neo-Confucianism, a system of Confucian thought influenced by Buddhism and Daoism (Taoism). The principles of Neo-Confucianism, including emphases on good conduct, wisdom, and appropriate social interaction, became part of Korean culture during this period. This value system energized the middle ranks of Koryo's officials, and their movement for social and political reform inspired the founding of the Choson dynasty by Yi Songgye.

A.  The Early Period Choson's early kings and its elite class of Confucianists established a social and political structure that withstood all challenges until 1910, achieving one of the longest periods of domination by a single dynasty in world history. Although heavily influenced by Chinese culture, Choson maintained a distinctive identity, as illustrated by its own unique alphabet, invented in 1446 by King Sejong. Peace and generally good government marked Choson's first 200 years, although disruptive divisions within the elite class began in the 16th century. While distracted by these struggles, Choson was invaded in 1592 by the Japanese, who wanted to use Korea as a transit route for the conquest of China. By 1598, however, Choson, with the aid of China's Ming dynasty and the efforts of its own naval hero, Yi Sunshin, had repulsed the Japanese. Still recovering from the Japanese invasion, Korea was again invaded, this time by the Manchus (first in 1627 and again in 1636). The Manchu conquest of China in 1644 brought new problems for Choson, but it also had the effect of stimulating the Koreans, temporarily cut off from Chinese influence, to more creatively develop their own culture.

B.  The Golden Age of Confucianism:  During the 17th and 18th centuries Choson enjoyed generally able kings and competent administration, although the court periodically witnessed factional struggles. Socially, the elite excelled at practicing the principles of Confucianism, as inspired by the Neo-Confucian movement of China. The examination system, a method of recruitment based on a test of the Confucian classics, was the basis for selecting most of the officials of the government. These elite scholar-officials possessed status, worth, and wealth. Confucian prejudice against business kept others from contesting the social position of the scholar-official.

C.  External Pressure:  During the second half of the 19th century, foreign powers sought to increase their influence on Korea. These advances were rejected by the Koreans, who believed the society they had achieved under the Confucian system needed little or nothing from outsiders other than China. Christianity, quietly introduced from China in 1784, was slowly and covertly propagated by underground French Roman Catholic missionaries. The Korean government, however, attempted to stop the spread of Christianity because it was not compatible with Confucianism. In 1864 the Taewon'gun (meaning "Grand Prince"), father of the boy-king Kojong, seized power, outlawed Christianity, and sought to curb foreign contact. He then faced military interventions by France (1866) and the United States (1871), which were attempting to establish trade relations with Korea. These attacks were repulsed. At the same time the Taewon'gun tried to eliminate corruption and refurbish the prestige of the state. The political reaction triggered by these reforms, however, resulted in his downfall in 1873. In 1876 the Japanese forced Korea to establish diplomatic relations in order to begin trade between the countries, thus weakening Korea's traditional ties to China. China then sought to neutralize Japan by promoting Korean ties with Western countries, beginning with the Korea-U.S. treaty of 1882. During the succeeding years, many Korean efforts were made toward modernization and reform, but these were frustrated by the continued influence of foreign powers. In 1895 Japan defeated China in the Sino-Japanese War, and ten years later Japan was victorious over Russia in the Russo-Japanese War. These victories cemented Japan's power on the Korean Peninsula, leading to the formal Japanese annexation of Korea and the end of the Choson dynasty in 1910.

JAPANESE RULE (1910-1945)  
Japanese domination of Korea formally began with the Protectorate Treaty (1905), forced on Korea after the Russo-Japanese War. Under this treaty, Japan assumed control of Korea's foreign relations and ultimately its police and military, currency and banking, communications, and all other vital functions. These changes were tenaciously resisted by the Koreans. In 1910 Japan formally annexed Korea when it realized Korea would not accept nominal sovereignty with actual Japanese control. From 1910 to 1919 Japan solidified its rule by purging nationalists, gaining control of the land system, and enforcing rigid administrative changes. In 1919 these measures, along with the general demand for national self-determination following World War I (1914-1918), led to what is known as the March First Movement. Millions of Koreans took to the streets in nonviolent demonstrations for independence, but the movement was quickly suppressed. In the following years Japan tightened its control, suppressing other nationalist movements. As the Japanese imperialist government became more militaristic and eventually went to war in China and then the Pacific and Southeast Asia in the 1930s and 1940s, Japan imposed several measures designed to assimilate the Korean population, including outlawing Korean language and even Korean family names. Korea was liberated from the Japanese by the Allied victory that ended World War II in 1945.

POSTWAR PARTITION  
Shortly before the end of the war in the Pacific in 1945, the United States and the Union of Soviet Socialist Republics (USSR) agreed to divide Korea at the 38th parallel for the purpose of accepting the surrender of Japanese troops. Both powers, however, used their presence to promote friendly governments. The USSR suppressed the moderate nationalists in the north and gave its support to Kim Il Sung, a Communist who led anti-Japanese guerrillas in Manchuria. In the south the leftist movement was opposed by various groups of right-wing nationalists. Unable to find a congenial moderate who could bring these forces together, the United States ended up suppressing the left and promoting Syngman Rhee, a nationalist who opposed the Japanese and lived in exile in the United States.

All Koreans looked toward unification, but in the developing Cold War atmosphere, U.S.-Soviet unification conferences (held in 1946 and 1947) broke up in mutual distrust. In 1947 both powers arranged separate governments, dividing Korea along the 38th parallel. U.S.-sponsored elections in 1948, observed by the United Nations (UN), led to the founding of the Republic of Korea in the south in August 1948. The north followed in September 1948 by establishing the Democratic People's Republic of Korea (DPRK). The division of Korea led to the Korean War two years later. A truce ended the fighting in 1953, but a permanent peace settlement has not been reached.