Korea under Japanese rule

• 1. Introduction

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  Korea under Japanese rule began on the 22nd of August 1910, when a treaty signed by Prime Minister Ye Wanyong and Japan's Minister of War, Terauchi Masatake, transferred the entirety of Korean sovereignty to the Emperor of Japan. Article 1 of that document left nothing ambiguous: it read that the Emperor of Korea conceded "completely and definitely his entire sovereignty over the whole Korean territory" to Japan. The colonial name given to the peninsula was Chosen, a Japanese reading of the Korean name Joseon. What followed was 35 years of transformation, suppression, and resistance that left a mark still felt across East Asia today. How did Japan bring Korea under its control? What did colonial life mean for ordinary Koreans? And why does this period remain so contested nearly eight decades after it ended?

• 2. Road to Annexation

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  On the 27th of February 1876, Japan forced Korea to open its ports under the Japan-Korea Treaty of 1876, an unequal agreement signed under the duress of the Ganghwa Island incident the previous year. Japan had itself been forcibly opened by the United States in 1854 and had rapidly modernized under the Meiji Restoration. Korea, still a tributary state of Qing China, had resisted. That resistance now crumbled.

  The following decades were filled with intrigue. In August 1882, the Mutiny of 1882, also called the Imo Incident, saw anti-Japanese forces kill a Japanese training cadre and attack the Japanese legation in Seoul. The subsequent Japan-Korea Treaty of 1882 required reparations of 500,000 yen to the Japanese government and permitted Japanese guards to be stationed in Seoul. Two years later, on the 4th of December 1884, a Japanese-backed faction called the Progressive Party attempted the Kapsin Coup, only to be suppressed by Chinese troops within days.

  In June 1920, war with China gave Japan its decisive opening. On the 3rd of May 1894, 1,500 Qing forces arrived in Incheon to suppress the Donghak Peasant Revolution. Japan seized the moment, attacked Seoul on the 23rd of July 1894, and started the First Sino-Japanese War. Victory over China in 1895 stripped Joseon of its tributary status and declared it independent, but independence proved fragile.

  The most shocking act of this period came on the 8th of October 1895, when Japanese minister to Korea Miura Goro orchestrated the assassination of 43-year-old Queen Min inside the royal palace Gyeongbokgung. Russian eyewitness Seredin-Sabatin, an employee of the Korean king, witnessed Japanese agents enter the palace and desecrate her body. Documents confirming Japan's direct role would not surface until 2001, when Russian Foreign Ministry archives yielded reports that included the testimony of King Gojong himself.

  Japan defeated Russia in the Russo-Japanese War, concluded by the Treaty of Portsmouth in September 1905, eliminating its last regional rival. King Gojong had even invited Alice Roosevelt Longworth, traveling with William Howard Taft, to the Imperial Palace on the 20th of September 1905, hoping to secure American sympathy. It was too late. The Taft-Katsura agreement of the 27th of July 1905 had already signaled that the United States would not interfere with Japan's ambitions in Korea. By November 1905, Korea was a Japanese protectorate, and its army was reduced from 20,000 to 1,000 men.

  Gojong made one final appeal, secretly sending three envoys to the Second Peace Conference in The Hague in June 1907. Among them was missionary and historian Homer Hulbert. The international delegates refused them access. One envoy, Yi Tjoune, committed suicide at The Hague out of despair. On the 19th of July 1907, Japan forced Gojong from power. On the 26th of October 1909, Korean nationalist Ahn Jung-geun assassinated former Japanese Prime Minister Ito Hirobumi in Harbin, an act that accelerated rather than halted the final annexation.

• 3. Japanization and Cultural Erasure

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  The ideological engine of colonial rule was a racial theory called Nissen dosoron, which asserted that Koreans and Japanese shared mythological ancestors and that Koreans were therefore inherently Japanese. In a speech in February 1944, Governor-General Koiso cited the ancient text Nihon Shoki to justify erasing Korean language, culture, and ethnic identity. This was not mere rhetoric.

  In 1911, a proclamation actually barred Koreans from taking Japanese names, aiming to preserve ethnic distinctions. By 1939, the policy had fully reversed. Imperial Decree 19 and 20, known as Soshi-kaimei, required Koreans to abandon their clan-based family names in favor of new surnames. In practice, many received Japanese surnames. A table of renaming applications in 1940 tells the story of the pressure applied: in February of that year, only about 15,746 households had applied, representing roughly 0.4 percent. By August, the figure had reached over 3.2 million households, or 80.3 percent. Whether that climb represented genuine acceptance or coercion remains debated.

  The physical landscape was reshaped as well. The royal palace Gyeongbokgung was partially destroyed beginning in the 1910s to make way for the Japanese General Government Building and a colonial exhibition. Hundreds of historic buildings in Deoksugung were also demolished. Japan's forces transported tens of thousands of cultural artifacts to Japan. As of April 2020-81,889 Korean cultural artifacts remain in Japan, according to the Overseas Korean Cultural Heritage Foundation.

  In 1925, Japan established the Korean History Compilation Committee, administered by the Governor-General. According to the Doosan Encyclopedia, some mythology was incorporated into its work. The committee promoted the disputed theory of a Japanese colony on the Korean Peninsula in antiquity, which scholar E. Taylor Atkins described as "among the most disputed issues in East Asian historiography." The National Palace Museum of Korea, originally built in 1908 to preserve Gyeongbokgung's treasures, was retained but renamed the Museum of the Yi Dynasty in 1938. Its displays reportedly placed traditional Korean art alongside modern Japanese art to portray Japan as progressive and Korea as backward.

• 4. Land, Labor, and Economic Extraction

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  By 1910, an estimated 7 to 8 percent of all arable land in Korea had come under Japanese control. That figure rose to 36.8 percent by 1916, to 39.8 percent by 1920, and to 52.7 percent by 1932. The mechanism was a cadastral survey conducted by Governor-General Terauchi Masatake's Land Survey Bureau, which recognized ownership only on the basis of written proof such as deeds and titles. Farmers with only traditional verbal cultivator-rights lost their land almost overnight.

  Taxation compounded the pressure. Rates in some cases exceeded 50 percent. Farmers who became tenant farmers had to pay over half their crop in rent. Between 1932 and 1936, per capita rice consumption among Koreans declined to half the level consumed between 1912 and 1916. Although coarse grains were imported from Manchuria to supplement the food supply, per capita food grain consumption in 1944 was 35 percent below the levels of 1912 to 1916.

  A 1939 statistic shows that Japanese interests controlled about 94 percent of total factory capital. Of large-scale enterprises with more than 200 employees, about 92 percent were Japanese-owned. Korean entrepreneurs were charged interest rates 25 percent higher than their Japanese counterparts, making it structurally difficult for large Korean businesses to emerge. As of 1942, Korean-owned capital constituted only 1.5 percent of total capital invested in Korean industries.

  The railway network that expanded across the peninsula was central to this extraction. Japan constructed railways from Busan northward to the Chinese border, and along the east coast as well. On the 1st of December 1937, the Northern East Coast Line opened to exploit mineral resources in South and North Hamgyong Provinces and Gangwon Province. It connected Yangyang and Wonsan and carried primarily timber and iron ore until the Korean War suspended operations in 1950. The Samcheok Development Company, established in April 1936 together with the Samcheok Railway Company, extracted anthracite coal that was valued, in the words of the period's records, for improving Japan's coal trade balance and reducing Japanese dependence on Chinese coal. Most of this coal was sent to Osaka, Nagoya, and Niigata. Railway construction itself relied on forced labor or workers paid very low wages, among them slash-and-burn farmers and people from destitute backgrounds.

  Scholar Atul Kohli at Princeton concluded that Japan's development model played a crucial role in Korean economic development, a model maintained after World War II. But economist Suh Sang-chul counters that the nature of industrialization was that of an "imposed enclave" with trivial benefit to ordinary Koreans. Scholar Song Byung-nak states that the average Korean's economic condition deteriorated during the period despite measurable growth in output.

• 5. Resistance and Independence

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  In January 1919, Emperor Gojong died suddenly, and anti-Japanese grief and anger swept the peninsula. Korean students in Tokyo issued a Declaration of Independence on the 8th of February 1919. Inspired by this, Koreans in Seoul read their own declaration aloud in Tapgol Park. What followed was the March 1st Movement, a nationwide series of peaceful protests that drew an estimated 2 million participants.

  The Japanese response was severe. Korean records state that over the following year, 46,948 people were arrested, 7,509 killed, and 15,961 wounded. Japanese figures counted 8,437 arrested, 553 killed, and 1,409 wounded. The gap between those accounts reflects the contested nature of the historical record that persists today.

  After the crackdown, Koreans fleeing the peninsula gathered in Shanghai and founded the Korean Provisional Government. In 1931, member Kim Ku founded the Korean Patriotic Organization, a militant arm of the government-in-exile. It carried out a 1932 assassination attempt on Emperor Hirohito and a bombing at a military rally in Shanghai, forcing the organization to flee to Chongqing, where it eventually received Chinese government support. There, Kim Ku founded the Korean Liberation Army, which fought in China and Burma. The army prepared to return to Korea and fight the Japanese in the Eagle Project, a mission that was overtaken by the atomic bomb droppings on Hiroshima and Nagasaki and Japan's sudden surrender.

  Armed resistance also continued from Manchuria. In June 1920, forces under Beom-do Hong ambushed and destroyed an Imperial Japanese Army unit at the Battle of Bongodong. Combined forces under Kim Chwajin and Hong then killed about 1,500 Japanese soldiers at the Battle of Cheongsanri. In retaliation, the Japanese Army committed the Gando Massacre, killing between 5,000 and tens of thousands of Korean civilians. One future leader who emerged from the guerrilla resistance in this region was Kim Il Sung, whose experiences there became the foundation of his political legitimacy after liberation.

  Within Korea, the Gwangju Students Independence Movement of the 3rd of November 1929 led to a tightening of Japanese military rule in 1931, after which freedom of press and expression were curtailed. Witnesses including Catholic priests reported that when villagers were suspected of sheltering rebels, entire populations were herded into buildings and massacred when the buildings were set on fire. In the village now known as Jeam-ri, a group of 29 people were gathered inside a church that was then burned, an event recorded as the Jeamni massacre.

• 6. Wartime Mobilization and Atrocities

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  From 1939 onward, Japan mobilized approximately 5.4 million Koreans to support its war effort. Of those, about 670,000 were taken to mainland Japan, including the Karafuto Prefecture, present-day Sakhalin. In Japan alone, 60,000 of these 670,000 mobilized laborers died. Estimates of deaths in Korea and Manchuria range between 270,000 and 810,000.

  Korean laborers were found across a vast geography of the Pacific War. At Tarawa Atoll, during the Battle of Tarawa, only 129 of 1,200 Korean laborers survived. According to testimonies preserved in Japanese records, Korean laborers on Mili Atoll were given what was described to them as "whale meat" but was actually human flesh from other dead Koreans. They rebelled after learning the truth and were killed in large numbers. On the island of Tinian, author Gaven Daws recorded in his book "Prisoners of the Japanese" that 5,000 Korean laborers were killed by Japanese forces, who feared having "hostiles at their back" when American forces arrived.

  Many Korean women and girls, mostly aged between 12 and 17, were forced into sexual slavery as "comfort women" for Japanese soldiers, often lured with false promises of factory or seamstress work. A 1944 U.S. Army interrogation report noted that these women received weekly medical checkups, but only to prevent the spread of disease to soldiers, not for their own health. A 1996 United Nations report concluded that "large numbers of women were forced to submit to prolonged prostitution under conditions which were frequently indescribably traumatic." Scholar Chizuko Ueno at Kyoto University cautioned against claims that these women were not forced, noting that potentially damaging official documents were destroyed in anticipation of Allied occupation. The Asian Women's Fund estimated the total number of women forced into this system reached anywhere from tens of thousands to hundreds of thousands.

  Military service itself carried its own burdens. Japan did not formally draft ethnic Koreans into its military until April 1944. Until that point, enlistment was officially voluntary but, as historian Pyo Young-Soo found in archival records, authorities used systemic coercive mechanisms, including issuing enlistment orders to secure compliance. By 1943, the raw number of applicants had grown from around 3,000 per year to over 300,000, yet the acceptance rate had dropped to 2 percent. After the war, 148 Koreans were convicted of Class B and C war crimes, 23 of whom were sentenced to death. Judge Bert Roling, who represented the Netherlands at the postwar tribunal, noted that Korean guards in prisoner-of-war camps were "sometimes far more cruel than the Japanese," a consequence of their placement in roles where proving loyalty to Japan was understood to be essential.

• 7. Liberation and Lasting Division

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  On the 15th of August 1945, Japan surrendered to the Allied forces, ending 35 years of colonial rule. American forces under General John R. Hodge arrived at the southern part of the Korean Peninsula on the 8th of September 1945. Soviet forces had already positioned themselves in the north. U.S. Colonel Dean Rusk proposed splitting Korea at the 38th parallel, a line proposed at an emergency postwar meeting. That division, intended as a temporary occupation boundary, hardened into the border between two states.

  The colonial legacy immediately became a matter of legal and moral contestation. The 1965 Treaty on Basic Relations between Japan and South Korea declared all treaties signed between the two empires on or before the 22nd of August 1910 "already null and void." Until that treaty, South Korea and Japan had no functioning diplomatic relations. In March 2010, on the 100th anniversary of the annexation, 109 Korean intellectuals and 105 Japanese intellectuals jointly declared the 1910 treaty null and void in simultaneous press conferences in Seoul and Tokyo.

  Within South Korea, the question of collaboration with Japan has proven particularly charged. Park Chung Hee, who became South Korea's most influential and controversial president, had served in the Japanese military and continued to praise it even after independence. The first ten Chiefs of Army Staff of South Korea had all graduated from the Imperial Japanese Army Academy. The "Name Restoration Order" issued on the 23rd of October 1946 by the U.S. Army Military Government allowed Koreans south of the 38th parallel to reclaim their Korean names. Many Koreans in Japan, however, chose to retain their Japanese names to avoid discrimination or to meet naturalization requirements.

  Relations between Japan and South Korea have oscillated between warmer and cooler periods ever since, regularly disrupted by disputes over the historiography of the colonial era. Former comfort women have continued to protest against the Japanese government from the early 1990s onward, seeking acknowledgment and compensation. The United States passed House Resolution 121 on the 30th of July 2007, asking Japan to formally address the comfort women issue and incorporate it into school curriculum. As of April 2020-81,889 Korean cultural artifacts remain in Japan, and the South Korean government continues active efforts to repatriate them.