Oma Castle

- Irreconciable conflict after god of war (11) fixture of situation-

Overview

Name: Oma castle (Oma-jo)
Alias:
Place: Kitadai Sanwa-ku Joetsu city, Niigata

Location: 37.1412147677949, 138.3724265037688
Type: Mountain Castle
Built: 14th century?
Remaining remnants: Clay walls and dry moats
Title:

Brief History

Continued from Part 10

Oma castle (大間城) is located at the south edge of the plateau prolongs westward from Karanoyama mountain, between Yasukura-gawa river and Kuwasone-gawa river at the east edge of Takada basin. Castle utilized the terrain separated from main body of the plateau like a claw by a valley, and the height from front hillside is about 80 meter.

Today Route 253 which is a main route connects Joetsu area and Uonuma area passes the northward of plateau along with Yasukawa-gawa river, but old Matsunoyama Kaido road ran along the south edge of the plateau, just the next of Oma castle. Instead, the north route was used as side roads toward Kashiwazaki area, passing Sakurazaka Toge pass or Gimyo Toge pass.

Anyway Oma castle was an important castle to control the traffic to and from Takada basin toward east, along with southward route currently used as Route 406 protected by Shirakanba castle (Niigata prefecture) and Ikefune castle (Niigata prefecture). All of these roads merges at the side of Nomine castle (Niigata prefecture) and headed eastward to Uonuma basin.

Castle protected roads to Takada basin

As Oma castle was a castle built for point protection rather than local administration, there is no information on the castle. As the castle is close to Nomine castle at about 5 kilometer east which was a large castle of the area and held by Kazama clan in 14th century, Oma castle might be built by Kazama clan as a watching place toward west and front side fort of Nomine castle.

In the beginning of 16th century, Tamekaga Nagao (1486-1543), the deputy governor of Echigo province (Niigata prefecture), raised his army against the governor Uesugi clan. Tamekage chased the governor who tried to run to Kanto region where the main family of Uesugi clan resided, and also fought with next governor came from Kanto region. Among this battle, Matsunoyama Kaido road which connects Joetsu area and Kanto region through Uonuma area became battlefield.

Kenshin Uesugi (1530-1578), son and successor of Tamekage Nagao, repeatedly made expeditions to Kanto region, to confront with Hojo clan which was the lord of Sagami province (Kanagawa prefecture) and ruined the main family of Uesugi clan. Kenshin Uesugi prepared Matsunoyama Kaido road and neighbor castles for expedition, and Oma castle might be renovated at this time.

Structure of Oma castle

Central area of the castle is a trapezoid shaped one of about 30 meter long, which is wholly surrounded by line of clay wall. Ahead of dry moat of over 10 meter wide, secondary area of rectangular one of about 50 meter long and 20 meter wide exists. At the northwest of secondary area small terraces said as the residence of retainers exists, this is connected to the backside climbing road.

Northwest part of central area which is connected to backside plateau is the weak point of the castle, then defense line is built by saddle point of plateau. Rectangular shaped entrance area is built at the front of secondary area, and large dry moat wholly covered the front side of central area and secondary area. Outside of outer dry moat in front of central area, a well is built at the top of the valley, and defense line consists of dry moat and clay wall is built over opposite peak.

At the south of central area, ahead of a line of dry moat, wide slope prolongs toward the halfway, where is a landing space of climbing road used as a small park. Each edge of this area is protected by layer of curved dry moats, and this space might be used as camping space of soldiers. Total size of the castle is about 200 meter long and 100 meter wide, and the size itself is not so large but the castle equips sophisticated defense facilities placed in small space.

Process of internal conflict

In 1578, Kenshin Uesugi suddenly died in ill, and his two adopted son Kagekatsu Uesugi (1556-1623) and Kagetora Uesugi (1554-1579) started internal conflict for successor named as “Otate-no-Ran”. Kagekatsu Uesugi was a person of Ueda Nagao clan, a relative of Kenshin, and Kagetora Uesugi came from Hojo clan.

At first Kagetora Uesugi who was supported by his home Hojo clan and its ally Takeda clan seemed superior, but Kagekatsu Uesugi turned Takeda clan to his side by negotiation, and after struggle drove back the attack of Hojo army to his native place Uonuma area by secure Sakado castle (Niigata prefecture) and heavy snow of winter season.

Due to the disappearance of the threat of Hojo army after October 1578, the situation became superior of Kagekatsu Uesugi. Kagetora Uesugi besieged at Otate castle (Niigata prefecture) near Kasugayama castle (Niigata prefecture), but Otate castle was originally an administrative place and had limited supplies compared with main base Kasugayama castle held by Kagekatsu Uesugi.

Struggle for supply line

Kagetora Uesugi was supported by local lords of Nagaoka area and Kashiwazaki area, thus the supply was gathered at Biwajima castle (Niigata prefecture) at Kashiwazaki city then transferred to Otate castle by marine and land transportation. In response to this, Kagekatsu Uesugi who had to finish the internal conflict before the arrival of spring executed both of direct attack to Otate castle and shut of supply line.

Land road which passes the coast line before Yoneyama mountain was the territory of Kakizaki clan at Saruge castle (Niigata prefecture) which subordinated to Kagekatsu Uesugi after internal conflict from the first stage of internal conflict then this route did not work. Next as both of Kashiwazaki area and Otate castle faced the Sea of Japan, marine transportation of supply was planned.

In response to this, Kagekatsu Uesugi tried to obstacle marine transportation from Hatamochi castle (Niigata prefecture), that directly faced the Sea of Japan and had a navy at the middle of Otate castle and Kashiwazaki area. Hatamochi castle assaulted the convoy of Kagetora Uesugi and prevented the transportation of supply, then Otate castle fell into severe short of supply in the beginning of 1579.

Disruption of supply line to Otate castle

As a last resort, Kagetora Uesugi tried to transport supplies by side mountain road, which goes upward along with Ukawa river and detours Yoneyama mountain then passed Sakurazaka Toge pass and goes down to the side of Yasukura-gawa river. This route was at the middle of Saruge castle and Nomine castle and could not prevent from both castles.

To shut this supply route, Kagekatsu Uesugi tried to seize the entrance of this route into Takada basin. Different from Nomine castle Oma castle still belonged to Kagetora Uesugi, but Kagekatsu negotiated with Oma castle then could turn to his side in February 1579. After that there was no supply sent to Otate castle, and Biwajima castle itself fell before the attack of Kagekatsu Uesugi in the beginning of March.

Of course Kagetora Uesugi tried to reopen supply route then Kagehiro Kitajo (1548-1579), the main general of the army, attacked Hatamochi castle but failed it. Furthermore in the beginning of February, due to the total attack of Kagekatsu Uesugi to Otate castle, Kagehiro Kitajo suffered severe injury and soon died. Lack of main general and supply upset the army of Kagetora Uesugi then soldiers escaped, then situation of conflict mostly fixed.

Reason of win and lose

There are various reason of win and lose, but major reasons are as follows. At first, Kagekatsu Uesugi had the army of his home Ueda Nagao clan loyal to Kagekatsu and under command, and Kagetora Hojo came from outside did not have his own army. Kagenobu Uesugi (?-?) who could command the army as a relative of Kenshin Uesugi died in the early stage of conflict then after that each supporters could not act unitary.

Next, Kagetora Uesugi relied on the support from external power such as Hojo clan or Takeda clan, but they did not work well. Takeda clan turned to Kagekatsu Uesugi, and Hojo clan faced Satake clan at another front could not send the reinforcement promptly. Slow move of Hojo clan result in the cease of help by heavy snow, then the priority of Echigo province was low compared with the conflict with Satake clan in Kanto region.

Finally compared to Kagekatsu Uesugi who took every measure to reverse inferior situation, the activity of Kagetora Uesugi was quite low. It might be a reservation as an outsider of Uesugi clan, or it might be the conflict unwillingly involved in. Even though losing authority, if Kagetora Uesugi moved to Nagaoka area from early stage of conflict, it is more easily to unite his supporters and contact with Hojo army.

Afterward of castle

At last in March 1579, Kagetora Uesugi left Otate castle and tried to ran to Shinano province (Nagano prefecture), but faced the betrayal of commander of Samegao castle (Niigata prefecture) he stepped in. Kagetora killed himself at Samegao castle, then internal conflict of two adopted sons ended. Oma castle might be kept for a while but might be abolished under intensification of castles.

Today no building remains but structure of the castle well remains over the plateau. The road slightly curves and runs at the south of castle toward the inside of the valley keeps the atmosphere of old Matsunoyama Kaido road. And the structures of the castle clearly show the role of this castle which protects them and control the transportation of the road from the top of the plateau.

Continue to Part 12

Access

30 minutes drive from Joshinetsu Jidoshado Expressway Joetsu-Takada interchange to parking space of Shinmeigu Shrine. 20 minutes walk from hillside to hilltop castle.