Japanese Castle guide in Japan castle Historical site Statue Introduction.

[Castle name]
Koyama castle
the castle fell down by the attack of Hojo Ujiteru

Koyama Castle is a flatland-mountain castle located in Shiroyama Town, Koyama City, Tochigi Province, it is also called [Gion Castle].
It is said that the castle was built by [Oyama Masamitsu] in Kyuan 4 year (1148).

Mr. Oyama was the descendant of [Fujiwara Hidesato] who had territory in Musashi Country, Masamitsu emigrated to Shimotsuke Koyama and started to name it Koyama.
During the South and North Dynasties, it was the residence of [Oyama Yasutomo] and the main castle for Mr. Oyama for generations. Koryaku 2 year (1380), in [Oyama Yoshimasa Chaos], [Ashikaga Ujimitsu] attaked Mr. Oyama who expanded his influence in Shimotsuke, and he successfully destroyed Mr. Oyama.

After that, Mr. Oyama’s former leader decided to let Mr. Yuki to rule this place, but he concerned about the dissatisfaction of the people and former vassals of Mr. Oyama, he decided to adopt a son from Mr. Yuki.
When entering Sengoku Period, Mr. Hojo started advance to North, and aimed to expand his influence to Shimotsuke and Hitachi. Therefore, Tensho 4 year (1576), Koyama Castle was attacked by Hojo Ujiteru and fell down. [Oyama Hidetsuna• Masatane] depended on [Satake Yoshishige] of Hitachi.

After that, Oyama became a very important place as the base in North Kanto for Mr. Hojo. Tensho 10 year (1582), [Oda Nobunaga]’s vassal [Takigawa Kazumasu] ruled Kanto and set base at Mayabashi Castle. In addition, Hojo Ujiteru successfully repatured Koyama Castle.
However, as a condition, Mr. Hojo should lend his power to them. Based on this, in Tensho 18 year (1590), in the conquest of Odawara, Mr. Hojo was forced to fight. and Mr. Oyama was replaced. Here, the prestigious Mr. Oyama was destroyed.

Keicho 12 year (1602), [Honda Masazumi] entered Koyama Castle. And Genwa 5 year (1619), he decided to move to Utsunomiya Castle. After that, [Koyama Castle] was abandoned.
[Koyama Castle Park] is built on the current castle ruins, and a monument is placed in front of the entrance od Koyama City Office.

[Address,access]
Shiroyama Town, Koyama City, Tochigi Province

[Map]