The first Korean Christians were prisoners captured during the Japanese invasions of 1592–8 and converted in Japan. The second introduction of Christianity was from China, where Korean envoys encountered Jesuit missionaries; a Korean was baptized in Beijing in 1784. By the end of the 18th cent. there were several thousand Christians in Korea and in 1831 an apostolic vicariate was established. Korean Christians were subjected to waves of persecution; 103 of those martyred in 1839–46 and 1866–7 were canonized in 1984. In the 1880s, following treaties between Korea and the W. powers, freedom of religion was granted. From 1884 numerous Protestant missionaries began work in Korea, mainly American Presbyterians and Methodists. When Japan, which had annexed Korea in 1910, was defeated in the Second World War, Korea was divided at the 38th degree of latitude. In North Korea the State tried to eradicate religious institutions. Many Christians migrated south; little is known of those that remain.
In South Korea Christianity is vigorous but fragmented. The Holy Spirit Association for the Unification of World Christianity (the ‘Moonies’), founded in 1954 by Sun Myung Moon, has spread to other countries. About 40 per cent of the population is Christian; of these over half belong to indigenous denominations.