Korea is the only Asian nation with a significant Protestant presence. One in five South Koreans professes the faith. With more than eight and a half million believers, Protestantism as an organized religion ranks second numerically, not far behind Buddhism, but in terms of power and influence, it is unrivalled. Protestants occupy a central position in the country’s politics, society, and culture. Western missionaries, mostly Americans, introduced Protestantism in the late 19th century. As bearers of Anglo-American civilization, the missionaries built not only churches but also modern hospitals and schools. Korean converts, however, quickly assumed leadership under a policy of self-propagation, self-government, and self-support. In the 1920s and 1930s, the church came of age under popular revivalists who commanded national audiences. The process of indigenization also involved the adaptation to local beliefs and practices, producing a distinctive Korean Protestant tradition. Moreover, because of Japanese colonization, Protestantism did not suffer the stigma of Western imperialism common in other mission fields. Many Protestants, in fact, became nationalist leaders. Following World War II, Korea suffered the division of the country and the Korean War. Protestantism was extinguished in the communist north, leading to a mass exodus to the south, but in South Korea, it thrived. Industrialization and urbanization provided opportunities for the churches to create a sense of community, but it was primarily the aggressive one-on-one proselytization and mass evangelistic campaigns that fueled the dramatic expansion. From the 1960s to 1980s, South Korea became the fastest-growing Christian population in the world. The growth stalled in the 1990s because of the church’s support for previous dictatorial regimes as well as scandals involving Protestant political and corporate leaders. Yet Protestantism today remains a vibrant force in South Korea, home to the largest churches in the world and the base for thousands of Korean missionaries.