As a colonial government established through “the annexation” of the Great Han Empire in 1910, the Government General initially used the offices of the old Japanese Residence-General in Korea (Tonggambu) at Namsan. In 1912 it decided to construct a new headquarters at Gyeongbokgung (palace) and appointed Georg de Lalande, a German architect, as the main designer. Construction started in 1916 and was completed in 1926. The new building was a 4-story, Renaissance-style building, made of ferroconcrete. It had a 50-meter high tower in the center and its interior and exterior were decorated with granite and marble. This grand new style of office building symbolized Japanese “civilization” and its majesty as ruler to the Korean people. Also, the new Government-General building was constructed in such a way that the original layout of Gyeongbokgung was damaged, also rearranging the spatial order of Seoul. Because the building was located between Gwanghwamun (gate) and Geunjeongjeon (hall), the Japanese moved Gwanghwamun to the north of Geonchunmun (gate). They rearranged the network of major roads to converge in front of the Government-General building. They also established the Gyeongseong City Hall on Taepyeongno in 1926, which was easily accessible from the Government-General building. As a result, the new urban axis of Seoul stretched from the Government-General building through the Gyeongseong City Hall, Seoul Station, and Yongsan.

In October, 1910, the Government-General rearranged colonial Korea’s regional administrative structure into a Do-Bu, Gun-Myeon system with 13 『do』 (provinces), 12 『bu』 (cities), 317 『gun』 (counties), and 4,356 『myeon』 (towns). As provincial capitals were generally the centers of local administrative from the Joseon dynasty (1392-1910), in many cases former provincial office (Gwanchalbu) buildings were used as provincial administration buildings, including in the following 6 provinces: Gyeonggi-do (Suwon), Gyeongsangbuk-do (Daegu), Jeollabuk-do (Jeonju), Chungcheongnam-do (Gongju), Chungcheongbuk-do (Cheongju), Hwanghae-do (Haeju), and Hamgyeongnam-do (Hamheung). In Gangwon-do, a royal villa in Chuncheon city was used as the provincial administration building. Gyeonggi-do provincial government used the building of the Department of Interior (Naebu) of the Great Han Empire as the provincial administration buildings moved to Gyeongseong (Seoul) in 1910. The two provincial governments, Gyeongsangnam-do (Jinju) and Pyeongannam-do (Pyeongyang), used the buildings of the local administrative office (Isacheong) of the Japanese Residence-General in Korea. In the 1920s and 1930s, 10 provincial administration buildings were newly constructed, starting with a building in Hamgyeongbuk-do (Nanam). Notably, the new provincial administration buildings of the 1920s were all Western-style buildings with pitched roofs, central towers, and long vertical windows. Those buildings were built in a grand and majestic style, to display colonial authority. Provincial capitals moved to other cities with new office buildings in several provinces, including Hamgyeongbuk-do (Gyeongseong to Nanam in 1920), Pyeonganbuk-do (Uiju to Sinuiju in 1923), Gyeongsangnam-do (Jinju to Busan in 1925), and Chungcheongnam-do (Gongju to Daejeon in 1931). The Government-General moved provincial capitals for “administrative convenience”, such as border security and accessibility to railroads. But this policy also rearranged the existing regional structure. Residents in the former provincial capitals such as Gongju and Jinju initiated campaigns against the transfer of provincial capitals.

As there was no legislative body in colonial Korea, ruling authority was concentrated in the administrative and judicial bodies. The buildings of the Government-General, the highest administrative institution, were constructed in the 1920s, as were the buildings of the highest judicial institution, the High Court. Korean courts were part of a three-tiered structure, comprising District Courts, Courts of Review, and the High Court. In October, 1928, the complex of three Gyeongseong (Seoul) courthouses—the Gyeongseong Regional Court, the Gyeongseong Court of Review, and the High Court—was established (currently the location of the Seoul Museum of Art). Earlier, the three Gyeongseong courthouses had used the buildings of the Great Han Empire’s Supreme Court (Pyeongriwon, 1899-1907) and the Hanseong court house. In 1911, the High Court moved to the former Uijeongbu (the highest decision-making governmental organization during Joseon period) building at Seosomun-dong (town). As the courts’ work load increased, the Government-General constructed a new Gothic-style courthouse complex and moved the three courthouses there. This made the Japanese authorities’ work much more efficient, but this work included the investigation and trial of Korean independent activists. Along with the nearby Seodaemun Police Station and Seodaemun Prison, the three Gyeongseong courthouses created a space in which Koreans who resisted colonial rule were punished.