When the kingdoms of Goguryeo, Baekje, and Silla were still enemies, the Gimpo region was a major arena of conflict among them. The region appeared in history as “Gimpo” in the 63rd year of the reign of King Jangsu of Goguryeo (475). After King Gyeongdeok of Silla unified the three nations in his 16th year of reign (757), Silla was reorganized into nine-states and five-regional capitals. The Gimpo Peninsula belonging to Hanju was divided into Gimpo-hyeon (Gimpo, Gochon, and Geomdan regions), Bujin-hyeon (Tongjin and Wolgot regions), Dongseong-hyeon (Haseong region), Suseong-hyeon (Yangchon and Daegot regions), and Gongam-hyeon (Gangseo-gu region in Seoul). These four hyeon (or counties) became the administrative counties of Jangje-gun (present day Bucheon), Gongam-hyeon under Yuljin-gun (present day Siheung). Also, in King Gyeongdeok’s 16th year, old Dongjahol-hyeon (or Dongsan) and Suihol-hyeon were renamed to Dongseong-hyeon (Jangje-gun) and Suseong-hyeon (Jangje-gun), respectively. In the early Goryeo Dynasty, Suseong-hyeon was changed to Suan-hyeon, but then eventually vanished from history after it was merged to Tongjin-hyeon in King Gongyang’s 3rd year.
During the reign of King Seongjong of Goyreo, Gimpo was a part of Gwannae-do (present day Gyeonggi and Hwanghae regions) and in the 9th year of King Hyeonjong’s reign (1018), it became the secondary township of Suju (Bupyeong-bu). Finally in the 2nd year of King Myeongjong (1182), Gimpo was separated from the district and a superintendent was appointed. During King Sinjong’s reign (1198), the King’s umbilical cord was buried in the region and hyeollyeong (county magistrate) was appointed. In King Gyeongdeok’s 16th year, Yangcheon’s old village Jechapaui-hyeon was renamed to Gongam-hyeon under the administration of Youljin-gun. It became a part of Suju in the 9th year of King Hyeonjong of Goryeo (1018), but it was again restored to Yangcheon in King Chungseon’s 2nd year (1310). A county magistrate was also appointed for the district.
In August of the 14th year of King Taejong’s reign (1414), Gimpo was merged with Yangcheon-hyeon and was renamed to Geumyang-hyeon. Geumyang-hyeon was then separated again in October of the same year, with Yangcheon being incorporated into Geumcheon (present day Siheung) and Gimpo into Bupyeong-bu. This was when the name “Gimpo” disappeared. In July of the 16th year of King Taejong’s reign, however, the name Gimpo was restored and Gimpo-hyeon was created. In the 10th year of King Injo’s reign (1632), Jangneung Royal Tomb was enshrined in Bukseongsan Mountain and Gimpo-hyeon was promoted to Gimpo-gun. During a reorganization in the 32nd year of King Gojong (1895), Gimpo-gun became a part of Incheon-bu and was ruled by a 4-grade gunsu (county governor) in the following year. During a reorganization that took place in the 16th year of King Gyeongdeok’s reign, Pyeonghoeap-hyeon, previously located in the Tongjin and Wolgot regions, was renamed as Bunjin-hyeon and became the secondary township of Jangje-gun, until it was renamed to Tongjin-hyeon during the Goryeo Dynasty. Tongjin-hyeon was merged with Dongseong-hyeon and Suan-hyeon in the 3rd year of King Gongyang’s reign (1391). This was the period when superintendents were appointed, and they were called hyeongam during the Joseon Dynasty (King Taejong’s 13th year (1413). In the 20th year of King Sukjong’s reign (1694), Tongjin-hyeon was promoted to Tongjin-bu, but then to Tongjin-gun during King Gojong’s reorganization (32nd year). In the following year, it officially became Tongjin-gun ruled by a 3-grade county governor.
During the nationwide reorganization of administrative districts in March 1914, Gimpo-gun , Tongjin-gun and Yangcheon-gun were integrated to “Gimpo-gun.” The reorganization led to 9 myeon in total: (a) Gunnae-myeon, Seokhan-myeon and Gohyeonnae-myeon (previously part of Gimpo-gun) incorporated to Gunnae-myeon; (b) Geomdan-myeon, Masan-myeon and Nojang-myeon incorporated to Geomdan-myeon; (c) Imchon-myeon and Gorantae-myeon incorporated to Gochon-myeon; (d) Bunae-myeon, Bogugot-myeon, Wolyeogot-myeon, Soigot-myeon, Gorigot-myeon, Banichon-myeon, Jiljeon-myeon, Bongseong-myeon, Daepa-myeon, Yangneung-myeon and Sanggot-myeon (previously part of Tongjin-gun) reorganized into Wolgot-myeon, Haseong-myeon, Yangchon-myeon and Daegot-myeon; and (e) Hyeonnae-myeon, Samjeong-myeon, Gabaegok-myeon, Namsan-myeon and Janggunso-myeon reorganized into Yangdong-myeon and Yangseo-myeon.
- Mar. 1, 1914 Incorporated Gimpo-gun, Yangcheon-gun and Tongjin-hyeon to Gimpo-gun (9 myeon)
- Jan. 1, 1963 Incorporated Yangdong-myeon and Yangseo-myeon to Seoul City (7 myeon) (Presidential Decree No. 1172)
- Jul. 1, 1973 Incorporated Ojeong-myeon and Gyeyang-myeon of Bucheon-gun (9 myeon) (Presidential Decree No. 2597)
- Oct. 1, 1975 Incorporated Ojeong-myeon to Bucheon City (8 myeon)
- May 1, 1979 Promoted Gimpo-myeon to Gimpo-eup (1 eup and 7 myeon) (Presidential Decree No. 9407)
- Feb. 15, 1983 Installed Tongjin-myeon (1 eup and 8 myeon) (Presidential Decree No. 11027)
- Jan. 1, 1989 Incorporated Gyeyang-myeon to Incheon City (1 eup and 7 myeon) (Act No. 4051)
- Mar. 1, 1995 Incorporated Geomdan-myeon to Incheon Metropolitan City (1 eup and 6 myeon) (Act No. 4802)
- Apr. 1, 1998 Promoted Gimpo-gun to Gimpo City (3 dong and 6 myeon) (Act No. 5458)
- Sep. 1, 2003 Divided Gimpo 3-dong into Sau-dong and Pungmu-dong (4 dong and 6 myeon)
- Jan. 1, 2004 Promoted Tongjin-myeon to Tongjin-eup (1 eup, 5 myeon, and 4 dong)
- Sep. 1, 2009 Promoted Gochon-myeon to Gochon-eup (2 eup, 4 myeon, and 4 dong)
- Nov. 14, 2011 Promoted Yangchon-myeon to Yangchon-eup (3 eup, 3 myeon, and 4 dong)
- Sep. 24, 2012 Installed Janggi-dong (3 eup, 3 myeon, and 5 dong)
- Oct. 28, 2013 Split Gurae-dong from Gimpo 2-dong (3 eup, 3 myeon, and 6 dong)
- Feb. 2, 2015 Split Unyang-dong from Gimpo 2-dong (3 eup, 3 myeon, and 7 dong)
- Apr. 18, 2017 Renamed Gimpo 1-dong as Gimpobon-dong
- Apr. 18, 2017 Renamed Gimpo 2-dong as Janggibon-dong
- Sep. 23, 2019 Split Masa-dong from Gurae-dong (3 eup, 3 myeon, and 8 dong)