* Image is for illustrative purposes only.Shichiknohe Castle (Kashiwaba Castle)
七戸城（柏葉城）
Shichiknohe Castle (Kashiwaba Castle) is a historic castle in Tōhoku dating from the Northern and Southern Courts period to Meiji (late 14th century–1873, when the castle was abandoned), whose lord was Shichiknohe Clan (Nanbu Clan branch) → Nanbu Clan → Shichiknohe Domain (Nanbu Clan sub-domain).
Overview
Construction and Origins of the Shichiknohe Clan
Shichiknohe Castle was a hilltop castle built on a plateau approximately 40 meters high near the confluence of the Sakutagawa and Wadagawa rivers in Kita District, Mutsu Province (present-day Shichiknohe Town, Kamikita District, Aomori Prefecture). Also known as Kashiwaba Castle. There are various theories regarding the time and founder of the castle's construction; while a tradition of construction by Nanbu Masanaga has long been transmitted, recent archaeological investigations have led to the increasingly accepted theory that Nanbu Masamitsu constructed it in the late 14th century. The castle lord, the Shichiknohe Clan, was a branch of the Nanbu Clan, which held territory in Mutsu from the Kamakura period. The clan is said to have descended from a family originating in Nanbu District, Kai Province, and governed the Shichiknohe region.
Activities During the Northern and Southern Courts Period
During the Northern and Southern Courts period, Shichiknohe Castle, together with Hachinohe Negijo Castle, served as a major stronghold of the Southern Court forces, demonstrating significant political and military importance in northern Tōhoku. During this era, various branches of the Nanbu Clan established bases throughout northern Ōu, each maintaining an independent sphere of influence. The Shichiknohe Clan persisted as a powerful regional clan while maintaining a certain distance from the Nanbu main house.
The Kunohe Masasane Rebellion and Shichiknohe Iekuni
A particularly important historical event in Shichiknohe Castle's history was the Kunohe Masasane Rebellion of Tenshō 19 (1591). Kunohe Masasane challenged the authority of the Nanbu main house and raised troops, and Shichiknohe Iekuni sided with Masasane. The rebellion was suppressed by a large army dispatched under the authority of Toyotomi Hideyoshi to implement the pacification of Ōu. Masasane was executed after surrendering. Shichiknohe Iekuni was also punished for participation in the rebellion; his domain was forfeited and the clan was eliminated, and Shichiknohe Castle came under direct control of the Nanbu main house.
Edo Period to Castle Abandonment and Restoration
With the beginning of the Edo period, Shichiknohe Castle was abandoned as a functioning castle following the implementation of the One Domain, One Castle edict (Genwa 1, 1615). However, a regional administrative office was established within the castle, and administrative functions continued. From Kanbun 4 (1664) onward, an administrative office was established under the jurisdiction of the Nanbu Morioka Domain. Following the Restoration of Imperial Rule (Meiji 2, 1869), Shichiknohe Domain was established and the castle site became the domain seat, but it was abolished by the Abolition of the Han System (Meiji 4, 1871), and the castle was formally abandoned in 1873. The castle's remains retain the form of earthen ramparts, moats, and baileys, and it was designated as a National Historical Site in Shōwa 16 (1941). Today, developed and open to the public as 'Kashiwaba Park,' visitors can see a reconstructed samurai residence and the castle's earthen ramparts.
Present Day
Ongoing excavation surveys are conducted by the Shichiknohe Town Board of Education, and medieval post-holes, ceramics, and iron artifacts have been unearthed. Explanatory plaques about Shichiknohe Castle have been installed within the castle site park, and it is utilized as a venue for learning about the political history of northern Ōu during the Northern and Southern Courts and Sengoku periods.
Connection to Swords
The Nanbu Clan was an important custodian of sword culture in Mutsu Province, and the Shichiknohe Clan, based at Shichiknohe Castle, actively collected and possessed swords under its authority. The terrain around Shichiknohe contains iron sand, which supported the supply of raw materials to blacksmiths throughout Tōhoku. During the Northern and Southern Courts period, the samurai band based at Shichiknohe Castle was equipped with uchi-katana and naginata for field combat, and it is believed that production and repair of arms also took place within the castle.
Highlights
- Medieval hilltop castle, a national historical site known by the alternate name Kashiwaba Castle
- Southern Court stronghold during the Northern and Southern Courts period
- Historic site where Shichiknohe Iekuni participated in the Kunohe Masasane Rebellion
- Headquarters of the Shichiknohe Clan, a branch of the Nanbu Clan
- Developed and open to the public as Kashiwaba Park
* Opening hours and admission fees are subject to change. Please check the official website before visiting.