Western missionaries arrived in Korea decades before the Japanese annexation of 1910, and they established a major presence before the advent of colonial rule. The missionaries initially clashed with the colonial state over state intervention in their religious affairs. Through a series of confrontations, the missionaries eventually gained key concessions which allowed them to expand their presence in Korea, especially in the cities of Pyongyang and Seoul. The reasons why Christian organizations flourished under Japanese colonial rule are often attributed to their nationalist reputation gained through the March First Movement, but this line of analysis tends to provide an incomplete picture. Through a careful examination of the process by which the Western missionaries became institutionalized in the colonial order through the pursuit of education, medicine, and other forms of ‘‘social work,’’ we may better understand the dynamics between state and religion in colonial Korea