Horace N. Allen (安連, 1858–1932) was born in a Christian family in Delaware, Ohio in the U.S. on April 23, 1858. After finishing his elementary, middle, and high school education in his hometown, he received Bachelor of Science from Wesleyan University in Ohio. Then, he studied medicine in Columbus for a year, and then he graduated from Miami Medical College in Cincinnati in March 1883.

Allen requested to be a missionary to the Board of Foreign Mission of the Northern Presbyterian Church in March 1883, just before he graduated. As he became a physician, he was sent to China as a missionary and arrived in China on October 11, 1883. When Allen arrived in China, however, he realized that the situation was different from what he thought of it. Since many missionaries were working in China already, it was not easy for him to find his own position. Subsequently, he could not adapt to Chinese life and wandered about for a year. Meanwhile, another missionary Dr. Allen had kept in contact with suggested him to go to Joseon, a neighboring country of China that just opened a port. After careful consideration of the suggestion, Allen confirmed that Joseon would need a foreign physician and made up his mind to accept his colleagues' recommendation. Accordingly, he requested to go to Joseon as a missionary to the Board of Foreign Mission of the Northern Presbyterian Church on June 8, 1884, and upon approval from the Board on July 22, he arrived in Jemulpo on September 20. Then, Allen became the first Protestant missionary in Joseon (Fig. 1). While H. G. Underwood (1859–1916) and H. G. Appenzeller (1858–1902) are usually mentioned as the first Protestant missionaries in Korea, Allen came before them. At that time, Joseon's port was opened and foreigners could come; however, Christian mission work was not freely permitted. As Allen could not disclose his status as a missionary openly, he worked as a physician affiliated in the U.S. legation on the surface, taking care of foreigners living in Joseon.

Due to the situation of Joseon in which missionary activities were not free, he had difficulty in performing as a missionary actively. It is thought that Allen mainly worked as a physician and then a diplomat accordingly. Nonetheless, it was not that Allen himself was passive as a missionary. The Chejungwon that Allen established served as not only a hospital, but also an outpost of full-scale missionary activities of the early Christian missionaries, such as Underwood. Thus, Allen's contribution as a missionary was significant. In addition, when he became the minister of the U.S., he gave many help to missionaries.

Allen first appeared as a physician in the Gapsin Coup, which occurred on December 4, 1884. Allen saved the life of Young-ik Min, a royal relative who suffered a fatal injury in the midst of the Gapsin Coup, through Western medical techniques. With this successful treatment as an opportunity, Allen gained confidence of the Korean king and proposed the establishment of a hospital to the government of Joseon. He suggested that if the Joseon government prepared a hospital, he will treat patients without receiving remuneration, and he will even give medical education to students. This was a quite good suggestion for the Joseon government, which was planning to accept new culture in various areas including the Western medicine after opening a port. The Joseon government immediately accepted the suggestion of Allen, and as a result, the Chejungwon, the first Westernized hospital, opened on April 10, 1885 (Fig. 2). The Chejungwon was run in dual form: Allen was in charge of the core function of hospital; and the government of Joseon was responsible for general management. After 1 year from the opening of the hospital, Allen established a medical school as he planned at the beginning and started medical education to selected students. The students began their studies with English and basic science, but due to a number of reasons, Chejungwon was not able to produce physicians who completed full-scale medical education. However, the contribution of Allen who opened the first hospital in Korea and started the first medical education must be remembered in the history of Korea.

Chejungwon was the first hospital in which the Western medicine was practiced, but there were similar institutions in which Joseon's traditional medicine was provided in the past. Those institutions, however, had thoroughly different patients according to patients' status. In other words, there were separate institutions for the royal family and common people. However, Allen was not bound to such customs of social discrimination in Joseon at that time, and treated all people equally regardless of their ranks and classes. Allen was the attending physician of the king of Joseon, but he gave medical treatment to many common people without discrimination.

As a physician, Allen left precious records on the medical situation in Joseon at that time. The records can be recognized through a medical report Allen published after 1 year from the opening of Chejungwon. In this report, Allen described overall hygiene situation in Joseon at that time, statistics on patients he treated, and other remarks in detail. Allen could treat malaria, which was prevalent in Korea at that time, with quinine, the special efficient medicine. He also demonstrated the excellence of Western medicine, which was different from Korean medicine, through a variety of procedures, including cataract operations (Fig. 3).

On the other hand, while giving all his heart and strength to patient treatment in Chejungwon, Allen realized that there were no female patients who visited Chejungwon because of Confucian customs regarding distinction between the sexes. Because women were reluctant to show their bodies to a strange foreign male doctor, they did not come to the hospital and ask for help even though they had serious diseases. When this situation was understood, Allen requested the Board of Foreign Mission to send a female physician and prepared a separate ward for women to treat and care for female patients.

In August 1887, the government of Joseon decided to establish a legation in the U.S. However, since there were no people who knew well about America, the government asked Allen for help. In this way, Allen could begin another career, as a diplomat. The Joseon government appointed Jeong-yang Park as the first plenipotentiary and Allen as a secretary of the legation. Allen resigned from his missionary position, left Jemulpo, and returned to the U.S. with Joseon's government officials at the beginning of October 1887. Qing Empire was dissatisfied with this independent act of diplomacy of Joseon, and thus, tried all possible efforts to disrupt this. For example, Qing attempted to summon the diplomatic mission itself, and in the U.S., they requested Korea diplomatic mission to come to the Qing legation in the U.S. first and conduct all diplomatic activities according to the instruction of Qing Empire. Jeong-yang Park would accept this request, but Allen convinced him to refuse the unreasonable demand and keep the dignity as an independent country, insisting that accepting the request is to give up the status as an independent country itself.

In June 1889, Allen resigned from the secretary of the Korean legation and came back to Joseon. He was missioned to pioneer a mission base in Busan from the U.S. Board of Foreign Mission and appointed as a missionary again. In October, he established the General Council of Evangelical Missions of U.S. Northern Presbyterian Mission and Victoria Mission.

After that, Allen was appointed as a secretary of the U.S. legation on July 9, 1890, and he was completely resigned from the missionary duty. However, when Dr. J. W. Heron (1856–1890), who was in charge of the Chejungwon at the time, died from dysentery, Allen was placed in charge again upon the request of the Board of Foreign Mission and the government of Joseon from August to almost half year. Allen was promoted to vice consul general on November 12, 1890 and appointed as the U.S. minister and consul general in Korea on July 27, 1897. Allen changed his career as above, but he sometimes led to solve problems caused by missionaries who were ignorant about the local situation since he was once a missionary.

As a diplomat, Allen helped Americans to win projects ordered by the government of Joseon. The typical examples were mining concessions in Woonsan gold mine and Seoul-Incheon railway construction rights. There were some critical views on such activities by Allen, but the one who gave these business licenses to Americans was King Gojong. In the situation where Japan, Qing, and Russia tried to take over Joseon at that time, the defensive measure Joseon could take, unfortunately, was to rely on a powerful nation. In King Gojong's view at that time, the U.S. was a strong nation, but unlike Japan, Qing Empire, or Russia, the U.S. did not have greed toward Joseon. The problem was that the U.S. not only had no particular interest in Joseon, but they also claimed nonintervention policy toward Joseon. Thus, the U.S. was dissatisfied with the missionaries intervening in Joseon's political situation and even warned them through the legation. By proposing rights and interests to attract the concern of the U.S., King Gojong attempted to make the U.S. intervene in Joseon actively, preventing invasions of Japan or Qing Empire.

Granting business licenses to American civilians, however, did not have any effect on the nonintervention policy of the U.S. toward Joseon, which was revealed in the Katsura-Taft Agreement. The Katsura-Taft Agreement was a secret agreement in which the U.S. agreed to recognize Japan's control over Joseon in return for the U.S. control over the Philippines. Allen, who was the minister of the U.S. in Korea at that time, showed strong opposition against such policy toward Joseon and complained to President Roosevelt. As a result, he was dismissed from the U.S. minister in 1905. After his dismissal, the U.S. legation in Korea was closed, and Allen left his long-time beloved Joseon on June 9, 1905 and arrived in the U.S. in September. He settled in Toledo, Ohio. Allen sent a congratulatory message to the 25th anniversary of Korean missionary of the U.S. Northern Presbytery, held in Seoul in September 1909. In 1930, Allen had to amputate both legs in a surgery because his health deteriorated, and he died at the age of 74, on December 11, 1932.

At the end of 19th century, Allen appeared in the modern history in Korea and performed various roles as a missionary, physician, and diplomat in this land. When determined by the period of activities, Allen worked as a diplomat for the longest time. Although he had affection toward this country and desired that Joseon would remain as an independent country, he had no effect on the flow of history that concluded with the Japanese annexation of Korea. In this sense, Allen as a diplomat is only a historic figure in the past. As a physician, on the other hand, Allen was not a man of the past. Although he worked as a physician for 3 years, which is not long, he is a symbolic character who introduced modern medicine in this country. His existence is vividly alive in Korean society to this day through the Chejungwon he established and Severance Hospital, which succeeded it.