Korean-style fortresses

• Japanese: 朝鮮式山城 (chousen shiki yamajiro)

Over the course of the Yamato Period, in the early centuries of the establishment of a Japanese state, a great number of Korean-style fortresses were constructed in Japan. Old fortresses dating to the 8th century and earlier can be found all over western Japan. Many of these sites have been identified with fortresses whose construction, repair, and destruction are described in detail in ancient chronicles such as Nihon Shoki and Shoku Nihongi. According to some interpretations of these texts, these fortresses were built under the guidance of, and at the orders of, various members of the Korean nobility or royalty.

Comparisons of these sites have been made to other Japanese fortresses, and to sites of the same period in both Korea and China. Though the theory persists of direct Korean involvement in the construction of these fortresses, alternative theories center around a fortress-building campaign in the late 7th century, by the Yamato court or more local Japanese authorities, against possible invasions from Silla and T'ang China. Many of the sites have been definitively dated to centuries earlier, however, and so, even if this theory holds for some sites, it does not encompass the majority.

Research on these sites is ongoing, and the questions of the purposes and origins of the fortresses, and their possible connections to Korea remain hotly debated among scholars, in part due to the nationalistic elements involved. Though some scholarship questions the identification of these fortresses with Korean origins, the Japanese term chōsen shiki yamajiro (朝鮮式山城, lit. "Korean style mountain castles/fortresses") continues to be used, for lack of a better term, to distinguish this particular class of structures. The term kodai yamajiro (古代山城, lit. "old period mountain castle/fortresses") is sometimes used, but its opponents argue that it can be interpreted too broadly; chōsen shiki yamajiro, even if not an entirely accurate description, denotes a very particular group of sites.

For the most part, researchers and specialists today doubt the appropriateness of the term "Korean-style fortresses," and continue to propose, research, and develop alternative theories as to the origins and purposes of these fortresses. However, mainstream sources such as newspapers and magazines, continue to represent the widely believed "traditional" version of events put forward by older scholarship, and to use the Korean-related terminology.

Research and debate

Cooperative research and discussions between the two countries, over the issue of determining the origins of these fortresses began in the 1970s. Fortresses of roughly the same type are extant in Korea, but only because they have been repaired or restored, either during the Joseon Period or in the 20th century, and thus arguments of their similarity to the Japanese fortresses in question are difficult to prove. On the other hand, enough of the ruins do remain that most scholars believe it obvious that these fortresses in question have far more in common with one another than with other Japanese fortresses, particularly later ones.

Much of the debate over these fortresses began in the late Meiji Period (1868-1912) and early Taisho Period (1912-1923), when geography and archaeology took off in Japan for the first time, and the classification of kôgoishi fortresses emerged. One key element of the debate was, and continues to be, whether these fortresses were built in the late 7th century, following Japan's defeat in the battle of Hakusukinoe, as defenses against a possible Silla/T'ang Chinese invasion of Japan, or whether they were built earlier, possibly independently from the policies or orders of the Yamato court. During the first decades of the twentieth century, a vibrant discourse was expounded regarding the time these fortresses were built, their similarities to one another and to Korean structures, the way in which they spread, and the reasons they were built. This debate continues among archaeologists today.

As it relates quite closely to the origins of Japanese culture and society, nationalistic bias on the parts of both Korean and Japanese scholars continues to have a major effect on this discourse.

Sites

Name	Kanji	Romanization	Year of Construction	Possible Locations	Current Situation
Takayasu fortress	高安城	Takayasu no ki	667	Kyûan-ji, Nara Prefecture; Takayasu-yama, Osaka Prefecture	The outer walls and water gate may have been found, but the extent of the fortress' remains, records of its history, and the area it covered have not been extensively investigated.
Yashima fortress	屋嶋城	Yashima no ki	667	Takamatsu, Kagawa Prefecture	Stone walls, earthworks, water gate, remains of the lookout towers and other remains have been found, but site has not been extensively investigated. Site of the 1185 battle of Yashima.
Nagato fortress	長門城	Nagato no ki	665	Shimonoseki, Yamaguchi Prefecture	Unknown
Ôno castle	大野城	Ôno jô	665	Dazaifu, Fukuoka Prefecture	Earthworks, stone walls, water gate, and remnants of buildings remain.
Kii castle	基肄城	Kii jô	665	Kiyama, Saga Prefecture	Ruins remain of the castle foundations, main gates, earthworks, stone walls, and water gate.
Kaneta fortress	金田城	Kaneta no ki	667	Tsushima, Nagasaki Prefecture	Ruins remain of castle walls, main gate, water gate, and lookout towers.
Kikuchi castle	鞠智城	Kikuchi jô	Nara-early Heian pds	Yamaga or Kikuchi cities, Kumamoto Prefecture	Ruins of 64 buildings or towers remain.
Ibara fortress	茨城	Ibaraki	Nara Period	Fukuyama, Hiroshima Prefecture	Unknown
Tsune fortress	常城	Tsuneki	665	Fuchû or Fukuyama cities, Hiroshima Prefecture	Unknown
Minô castle	三野城	Minô-jô	late 7th c.	Hakata, Fukuoka Prefecture	Unknown
Inazumi fortress	稲積城	Inazumi no ki	late 7th c.	Shima, Fukuoka Prefecture	Unknown
Mio fortress	三尾城	Mio no ki		Takashima, Shiga Prefecture	Unknown
Ki castle	鬼ノ城	Ki no jô	late 7th c.	Sôja, Okayama Prefecture	Ruins of stone walls, water gate, various buildings remain. Western gate, several other buildings, reconstructed in first years of 21st century.

See also

• Japanese castles in Korea (wajô, 和城)