was a

Sengoku period The was the period in History of Japan, Japanese history in which civil wars and social upheavals took place almost continuously in the 15th and 16th centuries. The Kyōtoku incident (1454), Ōnin War (1467), or (1493) are generally chosen as th ...

'' yamajiro'' located in Kai Province (present day

Yamanashi Prefecture is a prefecture of Japan located in the Chūbu region of Honshu. Yamanashi Prefecture has a population of 787,592 (1 February 2025) and has a geographic area of 4,465 km2 (1,724 sq mi). Yamanashi Prefecture borders Saitama Prefecture to the n ...

), constructed in the 1520s by the

Takeda clan The was a Japanese samurai clan active from the late Heian period until the late 16th century. The clan was historically based in Kai Province in present-day Yamanashi Prefecture. The clan reached its greatest influence under the rule of Taked ...

. Since 1991, the ruins have been protected as a National Historic Site since 1938. The castle is also known as the .

Background

The Takeda clan was a cadet branch of the

Minamoto clan was a Aristocracy (class), noble surname bestowed by the Emperors of Japan upon members of the Imperial House of Japan, imperial family who were excluded from the List of emperors of Japan, line of succession and demoted into the ranks of Nobili ...

, and gradually gained control over Kai Province from the late

Heian period The is the last division of classical Japanese history, running from 794 to 1185. It followed the Nara period, beginning when the 50th emperor, Emperor Kammu, moved the capital of Japan to Heian-kyō (modern Kyoto). means in Japanese. It is a ...

from their bases at Hakusan Castle and Yato Castle. From the

Kamakura period The is a period of History of Japan, Japanese history that marks the governance by the Kamakura shogunate, officially established in 1192 in Kamakura, Kanagawa, Kamakura by the first ''shōgun'' Minamoto no Yoritomo after the conclusion of the G ...

to the

, they were the ''

shugo , commonly translated as ' ilitarygovernor', 'protector', or 'constable', was a title given to certain officials in feudal Japan. They were each appointed by the shogun to oversee one or more of the provinces of Japan. The position gave way to th ...

'' of Kai Province, and

Takeda Nobutora was a Japanese ''daimyō'' (feudal lord) who controlled the Province of Kai, and fought in a number of battles of the Sengoku period. He was the father and predecessor of the famous Takeda Shingen. Biography Nobutora’s son was Harunobu, la ...

(1493-1573) selected a location near the center of the province to build his fortified residence and ''

jōkamachi The were centres of the domains of the feudal lords in medieval Japan. The ''jōkamachi'' represented the new, concentrated military power of the daimyo in which the formerly decentralized defence resources were concentrated around a single, cent ...

'' in 1519. This was the ''Tsutsujigasaki Yakata'' in what is now the city of

Kōfu is the capital Cities of Japan, city of Yamanashi Prefecture, Japan. , the city had an estimated population of 187,985 in 90,924 households, and a population density of 880 persons per km2. The total area of the city is . Overview Toponymy Kōfu ...

. Although a strongly-fortified manor house, its primary defenses were moats, and it was considered unsuitable to withstanding a siege. Nobutora therefore fortified a nearby mountain, Yōgaiyama, as a supporting castle and final redoubt with wooden rampartss and earthenworks defenses and built a

signal tower On a rail transport system, signalling control is the process by which control is exercised over train movements by way of railway signals and block systems to ensure that trains operate safely, over the correct route and to the proper timeta ...

on its summit.

Description

Yōgaiyama Castle occupies a narrow ridge, and consists of 20 terraces cut into the hillside. The route does not climb directly between terraces, but wanders back-and-forth, so as to expose any enemy to attack by defenders in the terrace above. The

inner bailey The inner bailey or inner ward of a castle is the strongly fortified enclosure at the heart of a medieval castle.Friar, Stephen (2003). ''The Sutton Companion to Castles'', Sutton Publishing, Stroud, 2003, p. 22. It is protected by the outer ...

is a rectangular area 80 x 30 meters at the highest point of the mountain, and was surrounded by clay walls. The enclosure has gates on its eastern and western sides. The total length of the castle is over 500 meters.

History

On 16 October 1521, Takeda Nobutora defeated the

Imagawa was a Japanese samurai clan that claimed descent from the Seiwa Genji by way of the Kawachi Genji. It was a branch of the Minamoto clan by the Ashikaga clan. Origins Ashikaga Kuniuji, grandson of Ashikaga Yoshiuji, established himself in t ...

at the Battle of Iidagawara. Nobutora faced an invasion of a 15,000-strong army from neighboring

Suruga Province was an Provinces of Japan, old province in the area that is today the central part of Shizuoka Prefecture. Suruga bordered on Izu Province, Izu, Kai Province, Kai, Sagami Province, Sagami, Shinano Province, Shinano, and Tōtōmi Province, Tōtōm ...

led by

Imagawa clan was a Japanese samurai clan that claimed descent from the Seiwa Genji by way of the Kawachi Genji. It was a branch of the Minamoto clan by the Ashikaga clan. Origins Ashikaga Kuniuji, grandson of Ashikaga Yoshiuji, established himself in ...

general Fukushima Masanari in support of the rebellion of the Ōi clan against Takeda rule. Nobutora sent his wife, the daughter of Ōi Nobusato, to the Yōgaiyama Castle for safekeeping. She gave birth to a son the day before Nobutora defeated the invasion, and in celebration of the event, Nobutora named their son, the future

Takeda Shingen was daimyō, daimyo of Kai Province during the Sengoku period of Japan. Known as "the Tiger of Kai", he was one of the most powerful daimyo of the late Sengoku period, and credited with exceptional military prestige. Shingen was based in a p ...

, “Katsuchiyo”. In 1576,

Takeda Katsuyori was a Japanese ''daimyō'' (military lord) of the Sengoku period, who was famed as the head of the Takeda clan and the successor to the legendary warlord Takeda Shingen. He was son-in-law of Hojo Ujiyasu, ''daimyō'' of Hojo clan. Early life H ...

ordered that the fortifications be renovated on a large scale. After the fall of the Takeda clan, the castle was controlled by a succession of retainers of

Tokugawa Ieyasu Tokugawa Ieyasu (born Matsudaira Takechiyo; 31 January 1543 – 1 June 1616) was the founder and first ''shōgun'' of the Tokugawa shogunate of Japan, which ruled from 1603 until the Meiji Restoration in 1868. He was the third of the three "Gr ...

, followed by

Toyotomi Hideyoshi , otherwise known as and , was a Japanese samurai and ''daimyō'' (feudal lord) of the late Sengoku period, Sengoku and Azuchi-Momoyama periods and regarded as the second "Great Unifier" of Japan.Richard Holmes, The World Atlas of Warfare: ...

, one of whom,

Katō Mitsuyasu was a retainer under the Toyotomi clan during the late Sengoku period of feudal Japan. Residing within Mino Province during his early life, Mitsuyasu took up arms in support of the Saitō clan and its leader, Saitō Dōsan. When Saitō Tatsuok ...

, made some further modifications to the defenses. However, after the

Battle of Sekigahara The Battle of Sekigahara (Shinjitai: ; Kyūjitai: , Hepburn romanization: ''Sekigahara no Tatakai'') was an important battle in Japan which occurred on October 21, 1600 (Keichō 5, 15th day of the 9th month) in what is now Gifu Prefecture, ...

in 1600, the castle was abandoned along with the Tsutsujigasaki Castle in favor of the new Kōfu Castle. At present, all that remains of the castle are some foundation stones and remnants of earthenworks of the

motte-and-bailey A motte-and-bailey castle is a European fortification with a wooden or stone keep situated on a raised area of ground called a motte, accompanied by a walled courtyard, or bailey, surrounded by a protective ditch and palisade. Relatively eas ...

structures. The castle was listed as one of the

Continued Top 100 Japanese Castles The is a list of 100 Japanese castle, castles, intended as a sequel of 100 Fine Castles of Japan. The castles were chosen for their significance in culture, history, and in their regions by the in 2017. Hokkaidō region Tōhoku region Kant ...

in 2017. In the southeastern direction from Yōgaiyama Castle, there is a branch castle ruin called Kumajō, which supplements the southern defense of Yōgaiyama Castle, and it is included in the National Historic Site designation. The Yōgaiyama Castle ruins can be reached by bus from Kōfu Station on the

JR East The is a major passenger railway company in Japan and the largest of the seven Japan Railways Group companies. The company name is officially abbreviated as JR-EAST or JR East in English, and as in Japanese. The company's headquarters are in ...

Chūō Main Line The , commonly called the Chūō Line, is one of the major trunk railway lines in Japan. It connects Tokyo and Nagoya, although it is the slowest direct railway connection between the two cities; the coastal Tōkaidō Main Line is slightly faste ...

References

Bibliography

* *Inoue Munekazu. ''Nihon no Meijo''. Yuzankaku publishing (1992).

External links