Japan Castle Explorer: Suyoshi Castle -Irreconciable conflict after god of war (3) supporters of Kagetora Uesugi-

Suyoshi Castle

-Irreconciable conflict after god of war (3) supporters of Kagetora Uesugi-

Overview

Name: Suyoshi castle (Suyoshi-jo)
Alias:
Place: Suyoshicho Nagaoka city, Niigata
Type: Mountain Castle
Built: 16th century
Remaining remnants: Clay walls and dry moats
Title:

Brief History

Continued from Part 2

Suyoshi castle (栖吉城) is located at Shiroyama mountain, one of about 250 meter height from hillside at 4 kilometer east from current Nagaoka city central. Castle site is a ridge spreads westward from north part of Uonuma Kyuryo hills which spreads north and southward along with Shinano-gawa river.

Shiroyama mountain is a corn shaped mountain and have good scenery of whole area of Nagaoka city including both side of Shinano-gawa river. Furthermore, castle site is a diverging point of the road from Nagaoka city area toward northeast to Tochio area and southeast to Yamakoshi area.

Origin of Suyoshi castle

Precise year is unknown but Suyoshi castle was built by local lord Koshi Nagao clan in the beginning of 16th century, replacing their former main base Zaodo castle (Niigata prefecture). Koshi Nagao clan was a large local lord of Nagaoka area, and a branch family of Nagao clan which served the deputy governor of Echigo province (Niigata prefecture).

Nagao clan was originally a descendant of Taira clan and lord of current Yokohama city. After the establishment of Kamakura Shogunate Nagao clan belonged to Miura clan, a major retainer of Shogunate, but due to internal conflict of Shogunate named Hoji Gassen in 1247 Nagao clan fell along with Miura clan.

Survived Nagao clan became the retainer of Uesugi clan which was originally a noble of Kyoto city but moved to Kamakura city then became the retainer of Kamakura Shogunate. After the fall of Kamakura Shogunate, Uesugi clan became an important retainer of Muromachi Shoghnate as Uesugi clan had marital relationship with Takauji Ashikaga (1305-1358) who established Muromachi Shogunate.

Foundation of three Nagao clans in Echigo province

Uesugi clan achieved the governor of center provinces of Kanto region such as Musashi province (Tokyo metropolis and Saitama prefecture), Sagami province (Kanagawa prefecture) or Kozuke province (Gunma prefecture), and was nominated as Kanto Kanrei, the counsel of Kamakura Kubo Highness which was a relative and representative of Muromachi Shogunate in Kanto region.

For Kozuke province and Echigo province, Uesugi clan took Nagao clan and placed them as the deputy governor. Nagao clan held Sanjo area, Nagaoka area and Uonuma area, where is a path from Kanto region and current route of Joetsu Shinkansen or Kanetsu Jidoshado Expressway.

Soon after entrance, Nagao clan was divided into three families which were Sanjo Nagao clan at Sanjo area, Koshi Nagao clan at Nagaoka area and Ueda Nagao clan at Uonuma area. Sanjo Nagao clan was the main family and served as deputy governor of Echigo province, then later moved to Joetsu city where the governor’s office existed.

Major branch family supported Nagao clan

Contrary to Sanjo Nagao clan, Koshi Nagao clan and Ueda Nagao clan remained at their territory. In 1507 Tamekage Nagao (1466-1543), the leader of Sanjo Nagao clan and deputy governor of Echigo province, raised army against the governor Fusayoshi Uesugi (1474-1507). Tamekage broke Fusayoshi and forced him to suicide.

Next Akisada Uesugi (1454-1510), Kanto Kanrei and the elder brother of Fusayoshi Uesugi, intruded into Echigo province for revenge of Fusayoshi. Tamekage once retreated to Sado island but came back to main land and broke Fusayoshi at the battle of Takamorihara. Fusayoshi died in the battle and followed to younger brother.

During this battle, both of Koshi Nagao clan and Ueda Nagao clan at first belonged to Uesugi clan but later turned to Tamekage Nagao and contributed to the victory of Nagao clan. Koshi Nagao clan achieved Suyoshi area at the east of Nagaoka city area, and built their main base Suyoshi castle on the mountain looked down Nagaoka area.

Structure of Suyoshi castle

Shiroyama castle has a two triangle shaped peak connected by saddle point like an eyewear, then castle spreads conforming to the shape of mountain. Western peak which faces Nagaoka city area is the core part of the castle, which consists of central area, secondary area and third area. Central area is a rectangular one of 50 meter long and 20 meter wide, and secondary area surrounds westward of central area.

Ahead of dry moat, third area which is oblong shaped of about 50 meter long and 20 meter wide works as an entrance area. The backside of central area is protected by dry moat, and from west to north line of west peak is protected by corridor area and vertical dry moats. Below of west peak there is a narrow and long riding space and well.

East peak is used as inner fort, and due to the name “old castle” and small size it might be built at first but then expanded into west peak. Rough structure is same as west peak which encircles core area by tall bluff and corridor area with vertical dry moats. Size of west peak is about 300 meter long square, and that of east peak is about 150 meter long square.

First position relative under Kenshin Uesugi

Both of Koshi Nagao clan and Ueda Nagao clan supported Tamekage Nagao, and Fusakage Nagao (?-?), the leader of Koshi Nagao clan, let his daughter marry with Tamekage Nagao. Kenshin Uesugi (1530-1578, renamed from Kagetora Nagao) was born from this lady then Kenshin Uesugi had the bloodline of Koshi Nagao clan.

After the retirement of Tamekage Nagao, at the confrontation between Harukage Nagao (1509-1553) and Kagetora Nagao, two sons of Harukage in 1548, Kagenobu Nagao (?-1578, later renamed to Kagenobu Uesugi) supported Kenshin Uesugi as his relative, contrary to Ueda Nagao clan which supported Harukage Nagao.

Finally Harukage Nagao left the leader position to Kagetora Nagao and retired, then Ueda Nagao clan rose against Kenshin but was broken and surrendered. The status of Ueda Nagao clan went down, then Kagenobu Uesugi was treated as the first position of relatives of Nagao clan. Kagenobu participated at many battles under Kenshin Uesugi and developed Nagaoka town.

Local lords belonged to Kagetora Uesugi

However, after the death of Kenshin Uesugi in 1578, two adopted sons Kagekatsu Uesugi (1556-1623) and Kagetora Uesugi (1554-1579) started internal conflict. Kagekatsu Uesugi was the person of Ueda Nagao clan, the rival of Koshi Nagao clan, thus once Kagekatsu Uesugi became the leader of Uesugi clan the situation of Koshi Nagao clan and Ueda Nagao clan might be reversed.

Furthermore, Kagekatsu Uesugi showed the attitude to centralize the power of Uesugi clan, suppressing large local lords. Local lords of middle part of the province including Koshi Uesugi clan still kept measurable independence from Uesugi clan but this independence might be deprived or decreased under Kagekatsu Uesugi.

Considering this, relatives of Uesugi clan such as Koshi Nagao clan or Sanbonji Uesugi clan supported Kagetora Uesugi. Besides, local lords of middle part of the province such as Hidetsuna Honjo (?-?) at Tochio castle (Niigata prefecture), Haruie Kakizaki (?-1578) at Saruge castle (Niigata prefecture) or Takahiro Kitajo (1517-1587) at Kitajo castle (Niigata prefecture) supported Kagetora Uesugi.

External power supported Kagetora Uesugi

As Kagetora Uesugi was originally the son of Ujiyasu Hojo (1515-1571), the leader of Hojo clan which was the warlord of Sagami province (Kanagawa prefecture), of course Hojo clan supported Kagetora Uesugi. And Hojo clan was a large warlord spread to large part of Kanto region and had connections with other warlords, external warlords belonged to Kagetora Uesugi based on the communication with Hojo clan.

Especially Katsuyori Takeda (1546-1582), the warlord of Kai province (Yamanashi prefecture) and son of Shingen Takeda (1521-1573) who was fatal rival of Kenshin Uesugi, married with the daughter of Ujimasa Hojo (1538-1590) and allied with Hojo clan. Even though declined by the defeat of the battle of Nagashino in 1575, Takeda army was still strong and existed at the next of the border.

At northward, two strong warlords Date clan, a traditional warlord which held Fukushima basin and Yonezawa basin, or Ashina clan which was the warlord of Kurokawa castle (Fukushima prefecture, later Aizu Wakamatsu castle) at Aizu basin formerly failed in intervention to Echigo province belonged to Kagetora Uesugi and waited for the chance of intrusion.

Tactics of Kagetora Uesugi

Echigo province has “T” letter shape, and Kagetora Uesugi seized center point of T letter but three edges are held by Kagekatsu Uesugi. Kagetora could stop the communication between three territories of Kagekatsu, but Kagetora himself was encircled at Otate castle at the western edge of the province held by Kagekatsu.

Different from Kasugayama castle (Niigata prefecture) where Kagekatsu captured, Otate castle where Kagetora besieged was an administrative office then had limited stock of supplies. It was necessary for Kagetora Uesugi to break the siege of Kagekatsu Uesugi and make contact to his side castle at middle part of the province, to bring supplies to Otate castle.

Furthermore, ahead of the three edges of “T” letters, external powers such as Takeda clan, Hojo clan or Ashina clan existed connecting to Kagetora Uesugi. For Kagetora Uesugi who had inferior army in the province, it was necessary to request the intrusion of external powers to Echigo province. From the status of Kagetora it seemed easy but actually not so, and this fact forced Kagetora to the corner.

Fall of Koshi Nagao clan and afterward of castle

Kagenobu Uesugi besieged at Otate castle and fought as a main force of Kagetora Uesugi army to break the siege of Kagekatsu Uesugi. But in June 1578, Kagenobu died in the battle of Kotahama at the next of Otate castle, before the attack of Kegekatsu Uesugi. Koshi Uesugi clan lost its leader and later lost Suyoshi castle then was ruined.

After the cease of internal conflict, Suyoshi castle was given to Nagachika Kawada (1542-1581), the close general of Kenshin Uesugi and who protected Ecchu province (Toyama prefecture) at Matsukura castle (Toyama prefecture). Nagachika became the leader of Suyoshi Nagao clan but did not use the surname of Uesugi from consideration.

Nagachika succeeded the territory and castles of Koshi Nagao clan, but soon died in ill before pressure of central ruler Nobunaga Oda (1534-1582) to Ecchu province. Suyoshi castle became the direct command castle of Kagekatsu Uesugi until the movement of Uesugi clan to Aizu basin in 1590, and was abolished at that time.

Today no building remains but structure of castle well remain on the mountain, even though covered by bush. Due to sheer cliff of the mountain it is a bit hard to reach to the castle but this contribute to good scenery of Nagaoka area at westward from the castle site.

This scenery also might be the sight of Kagenobu Uesugi, who looked from Suyoshi castle at his territory and out of sight Kasugayama castle, and decided the attitude toward internal conflict, even though resulted in the fall of Suyoshi Nagao clan.

Continue to Part 4

Access

30 minutes drive from Kanetsu Jidoshado Expressway Nagaoka interchange to parking of Suyoshi Jinja Shrine at southeast edge of Shiroyama mountain. 30 minutes walk from shrine to hilltop castle.