Hongseong (Hangul/Hanja: 홍성군/洪城郡) is the Provincial Capital of Southern Chungcheong, Republic of Korea; regardless of its status as county. The county is the ancestral seat of Yeoyang Jin Clan where Yeoyang is one out of eleven Prefectures in Hongseong during Goryeo Period, now known as Janggok-myeon Commune. It is the hometown of Choi Yeong - Goryeo General during the Declination of Goryeo Dynasty, Seong Sammun - one of the Six Martyred Ministers a.k.a Sayukshin and Baeg-ya Kim Jwa-jin, the great-grandfather of Korean Actor, Song Il-gook on his mother's side - anarchist in the verge of Japanese Colonization Period.
Hongseong is bordered with Seosan City on North, Yesan County on Northeast, CheongYang County on Southeast, Boryeong City on South and Anmyeon Island, Taean County on West which is separated by Cheonsu Bay. The postal codes of Hongseong County start from 32200 (10~484 GalsanSeo-gil, Galsan-myeon) to 32299 (274~423 Hongjangnamno 272beon-gil, Janggok-myeon).
Hongju was perviously known as Unju (운주/運州) during the reign of King Seongjong Wang Chi of Goryeo. A government official called, dodanryeonsa, was sent in 995 to govern the area, and jijusa in 1012. Then, it was renamed as Hongju (홍주/洪州). Its administrative unit status was raised to a "mok" in 1358, and a jijusa began governing the area in 1368.
Gyeolseong-gun was originally called Gyeonggi-hyeon in the Baekje Kingdom, but it came to be known as Gyeolseong in the Silla period and was the Yeonghyeon of Seorim-gun. In 1018 during Goryeo Dynasty, it became transferred to Unju, and had a gammu in 1172. Many of the residents fled the area when it was invaded by the Japanese Pirates during the reign of King Woo. For this reason, a fortress was built to attract more settlers.
In 1413 - 13th Reigning Year of King Taejong Yi Bang-won of Joseon, a hyeongam was sent to govern the area. Then in 1895, its administrative unit status was raised to "gun" and in 1914, Hongju-gun, Gyeolseong-gun and some of the areas of Boryeong-gun were integrated together to establish Hongseong-gun. The administrative unit status was raised for Hongju-myeon to Hongseong-eup in 1941 and Gwangcheon-myeon to Gwangcheon-eup in 1942.
According to the nationwide changes to the administrative divisions in February 1983, Daesa-ri, Gobuk-myeon, Seosan-gun and Wa-ri, Gyeolseong-myeon were transferred to Galsan-myeon, Wollim-ri, Daepyeong-ri and Unyong-ri of Hongdong-myeon to Gwangcheon-eup, Jung-ri, Gyeolseong-myeon to Seobu-myeon, as well as Naebeop-ri of Hongbuk-myeon and Guryong-ri of Hongdong-myeon to Hongseong-eup.
The changes in the administrative division resulted in 2 towns and 9 communes: Hongseong-eup and Gwangcheon-eup as well as Galsan-myeon, Gyeolseong-myon, Guhang-myeon, Geumma-myeon, Seobu-myeon, Eunha-myeon, Janggok-myeon, Hongdong-myeon and Hongbuk-myeon.
In 2012, the provincial administration of Southern Chungcheong was moved to Naepo New City, Hongseong from Seonhwa-dong, Daejeon Jung-gu. A year later, Chungnam Provincial Police Agency which was previously located same place as Southern Chungcheong Provincial Government moved to the same area but in different county - Sapgyo-eup in Yesan County. The old provincial office in Seonhwa-dong was gazetted as Korean Republic Tangible Asset No. 18.
The county office is located at 27 Amun Alley/Amun-gil, Ogwan-ri 98-beonji, Hongseong-eup with its postal code: 32228. The chief of the county is Kim Seok-hwan (Saenuri). In the other hand, Hong Mun-pyo (Saenuri) served as the assemblyman for Yesan and Hongseong Counties in 20th Session of Gukhoe (2016-2020). Hongseong County contains two towns (eup) and nine communes (myeon) as shown on the map below (in Hangul and Hanja).