Nakayama Castle (Dewa)
-Land snail like castle at the border-
Name: Nakayama castle (Nakayama-jo)
Place: Nakayama Kaminoyama city, Yamagata
Type: Mountain Castle
Remaining remnants: Stone walls and clay walls
Nakayama castle (中山城) is built at Tenshu-yama mountain, one of about 100 meter tall from hillside at the west of current Uzen Nakayama station. Castle site at nearly north edge of narrow path prolongs with Mae-kawa river and connect Yamagata basin, the center of current Yamagata prefecture, and Yonezawa basin which is another flat area of the prefecture in southern part.
Important point connects two basins
Historically this point has been an important chokepoint of Yonezawa Kaido road run between two basins. There is another road connects two basin along with Mogami-gawa river, but this route passes detour route passes narrow valley, and does not directly arrive at the center of current Yamagata city. On the other hand, Yonezawa Kaido road is a short cut route directly connected three large towns of the area, it mean Yamagata town, Kaminoyama town and Yonezawa town, and prolongs over stable land.
Furthermore, this road merged with Uzen Kaido road which divided from main street of Oshu Kaido road and passes Oshu mountains, thus convenient for transportation toward Fukushima area of Sendai area. Even now, main arteries of the area such as Yamagata Shinkansen line or Route 13 passes just in front of the castle. As castle site is a small flat place before the narrow path, it is an appropriate place to build a castle toward Yamagata basin from Yonezawa basin.
Two strong powers at two basins
Being next to each other in the same Dewa province (Yamagata prefecture), throughout medieval era, Yonezawa basin and Yamagata basin were governed by different power. At Yamagata basin, there was Mogami clan which was a branch family of Shiba clan, a high class retainer of Muromachi Shogunate, and named Ushu Tandai (general governor of Dewa province). On the other hand, Yonezawa basin was captured in the end of 14th century by Date clan, which was originally a local small lord but gradually grew their power into the strongest power in Tohoku region.
Since the beginning of 16th century, Mogami clan and Date clan fiercely fought at the border. At first in 1514, Tanemune Date (1488-1565), the leader of Date clan, assaulted Mogami army and broke it at Hasedo castle, just at the next of Yamagata castle which was the main base of Mogami clan. Mogami clan had to subordinate to Date clan, and branch family of Mogami clan such as Tendo clan or Sagae clan left Mogami clan and made independent alliance.
Construction toward north
But this time in 1542, a large internal conflict named Tenbun-no-ran occurred at Date clan, between Tanemune Date who tried haste centralization and his son Harumune Date (1519-1578). The power of Date clan significantly declined during 6 years conflict, and Yoshimori Mogami (1521-1590), the leader of Mogami clan, left Date clan and returned to the independent lord, then recovered deprived castles.
After the cease of internal conflict, Harumune Date who overcame his father and became new leader of Date clan moved their main base from Kori Nishiyama castle to Yonezawa castle. Now Date clan and Mogami clan faces only 30 kilometer apart, and the border area of Yamagata basin and Yonezawa basin became a tensioned area. Both power built many castle at hilly border area, and Nakayama castle was one of such castle. It is said that Nakayama castle was built by Nakayama clan, a local retainer of Date clan around 1570 as a front fort against Mogami clan.
Castle like land snail
Nakayama castle consist of main part at Tenshu-yama mountain which is a corned shaped one separated from backside mountains by valleys, small hill named Maemoriyama-tate at the east of the castle, and saddle point connects them. Combination of round shaped mountain and rectangular hillside area with small tip at the end exactly seems like a land snail.
In addition to its external shape, the structure of the castle also resembles the vortex shell of land snail. The rough structure of hilltop area is a counterclockwise going down four areas from hilltop to hillside. The central area at the top of the mountain is an oblong shaped area of 50 meter long and 30 meter wide, protected by a line of clay wall.
At the north edge of central area, there is a ruin of the basement of main tower which is about 10 meter long square and had a ruin of broken stone walls. This tower might be built to directly shoot a small valley which is a center of vortex and might be used as a backside gate of the castle. Considering its size, a two story tower might be existed on this basement.
Advanced castle with front forts
The main route from hillside area to this hilltop area passes three areas, and each of these areas are well shaped and protected by folded path climbs steep slope. Especially the gate between secondary area and third area is a secure one which turns three times and exposed at the attack from upper side. Outside of these core areas, corridor area surrounds whole part of the mountain.
At the east of hill, there is a large flat space of about 100 meter long square. This place might be originally surrounded by clay wall, and used as a hillside residence of the lord. Ahead of this flat space, Maemori-yama fort which was originally used as a fort of Date clan worked as a front fort to control the road attack the enemy which battering the main gate from backside.
Furthermore, several front forts were built at neighbor hills such as Monomi-yama hill or Katakura-yama hill, worked together with Nakayama castle itself. The castle itself is a middle sized one of about 300 meter long and 150 meter wide, but considering these front fort it was a prominently secure and large fortress compared with neighbor castles at the same era.
Improvement by Gamo clan
Mogami clan and Date clan both grew their power at excellent leaders such as Yoshiaki Mogami (1546-1614) or Masamune Date (1567-1636). To cope with forcible expansion of Masamune, Yoshiaki sometimes attacked Masamune along with neighbor lords, but Date army including Nakayama castle well protected their territory.
Finally Masamune who broke Ashina clan became the ruler of south half of Tohoku region, but finally Date clan and Mogami clan had to subordinate to central ruler Hideyoshi Toyotomi (1537-1598) in 1590. Next year Masamune lost Yonezawa basin and was transferred to current Sendai area, and Ujisato Gamo (1556-1595), an excellent general under Hideyoshi who already held Aizu Wakamatsu castle also became the lord of Yonezawa basin.
To reign vast and separated territory, Ujisato reformed branch castles into a modern one equips stone walls or folded gates, same other branch castles such as Miharu castle, Inawashiro castle, Nihonmatsu castle or Naganuma castle. As a north gate of the territory toward Yamagata basin, structure of Nakayama castle including stone built basement of main tower might be built under Gamo clan. Ujisato Gamo placed his brave general Satoyoshi Gamo (?-1598) as a commander of Nakayama castle.
Starting point of total attack
After the death of Ujisato, Hideyoshi moved Kagekatsu Uesugi (1556-1623), the lord of Echigo province (Niigata prefecture) to the former territory of Gamo clan as a restraint to Masamune Date and Ieyasu Tokugawa (1543-1616), the largest lord under Toyotomi government. After the death of Hideyoshi, Ieyasu Tokugawa and Mitsunari Ishida (1560-1600), the chief administrative staff of Hideyoshi, fought for next hegemony, then Kagekatsu Uesugi who supported Mitsunari became hostile with Masamune Date and Yoshiaki Mogami belonged to Ieyasu.
In 1600, Ieyasu lead large army and once marched toward Uesugi clan but returned to Kinki region facing the rise of Mitsunari. Looking at this opportunity, Uesugi clan planned to unite Tohoku region and made total attack toward Yoshiaki Mogami. In addition to the main force lead by Kanetsu Naoe (1560-1620) intruded into Yamagata basin from westward, a detached army left Nakayama castle and attacked Kaminoyama castle held by Mogami clan.
But this army faced sudden attack of small Mogami army and could not fell Kaminoyama castle. Main army of Mogami clan also stagnated at Hasedo castle, and in the meantime, Ieyasu Tokugawa broke Mitsunari Ishida at the decisive battle of Sekigahara, then Uesugi army stopped their attack toward Mogami clan and retreated.
Afterward of castle
Uesugi clan finally subordinated to Ieyasu Tokugawa then survived as a feudal lord under Edo Shogunate but lost their territory except for Yonezawa basin. Nakayama castle might be abolished under Ikkoku Ichijo-Rei (one domain one castle rule) published in 1615, but Yonezawa domain continuously placed guard post at the side of the mountain. After the abolishment of castle, Nakayama town prospered as a posting town of Yonezawa Kaido road.
Now all building was lost but structure of the castle including ruin of main tower basement well remain on the hill. Well planned and shaped terraces of the castle shows an importance of this castle both for offensive and defensive purpose. Being built at late period and in spite of short live less than 50 years, simple but consistent plan of the castle with clear usage and well constructed structures has a powerful impression not seen in neighbor castle. Even though having lovely exterior, it was a dreadful land snail with secure shell and flexible tactics.
15 minutes walk from JR East Ou Honsen-sen line Uzen-Nakayama station. 20 minutes drive from Tohoku Chuo Jidoshado Expressway Yamagata-Kaminoyama interchange to hillside parking. 15 minutes walk from hillside to hilltop castle.