Sunday, February 14, 2021

 Mikawa Kameyama Castle

-Cavalry VS matchlock gunner (2) estrangement of marginal local lords-



Name: Kameyama Castle (Kameyama-jo)

Alias: Tsukude-jo (Tsukude castle)
Place: Tsukude-Kiyotake Shinshiro city, Aichi
Type: Hill Castle
Built: 15th century?
Remaining remnants: Clay walls and dry moats 

Brief History

Kameyama castle is located at the north half of leaf shaped hill of 300 meter long and 100 meter wide, which is about 30 meter height from hillside at the backside of tourist station “Tsukude Tezukuri-Mura”. South-edge of Tsukude area has reverse “C” latter shaped flat land encircling Monju-yama mountain, and castle site can observe this curved flatland.

Tsukude area is a 10 kilometer long valley at 500 meter height above sea level at the south edge of Mikawa-Kogen height. This valley is formed by Tomoe-gawa river which is the tributary of Yahagi-gawa river flows westward, and another Tomoe-gawa river which is the one of Toyo-kawa river flows eastward. 

The northward is connected to Shitara area toward Mino province (Gifu prefecture) or Shinano province (Nagano prefecture), and southward is close to Shinshiro area ahead of sheer slope. Because of this geographical situation Tsukude area works as the hub of traffic at east half mountain area of Mikawa province (east half of Aichi prefecture).

Origin of Okudaira clan and Kameyama castle

Precise year is unknown but Kameyama castle was built by local lord Okudaira clan in 15th century. Okudaira clan was originally a local lord of Kozuke province (Gunma prefecture) and a descendant of local samurai Kodama clan. But among the conflict between Muromachi Shogunate and Kamakura Kubo highness the clan fell then moved to Mikawa province (east half of Aichi prefecture) seeking for frontier.

Okudaira clan entered into Tsukude area united the valley gathering local residents and became a local lord. From the eastward to southward of Tsukude area Toyo-kawa river curvedly flows, and along the river there are castles of another local lord Suganuma clan such as Damine castle (Aichi prefecture) at upstream, Nagashino castle (Aichi prefecture) at middle, and Noda castle (Aichi prefecture) at downstream.

Due to closeness Okudaira clan coordinated with Suganuma clan, then Okudaira clan, Damine Suganuma clan and Nagashino Suganuma clan were unitedly called as “Yamaga Sanpo Shu” (three local lords at mountain area). When Imagawa clan which was the governor of Suruga province (middle part of Shizuoka prefecture) expanded their power into Mikawa province at the beginning of 16th century, Okudaira clan followed to Imagawa clan along with Suganuma clan.

Survival among strong warlords

In 1529, Kiyoyasu Matsudaira (1511-1539), the young leader of Matsudaira clan which was the lord of Okazaki castle (Aichi prefecture) and grandfather of Ieyasu Tokugawa (1543-1616), united west half of Mikawa province and ascended to east half of the province. 

Looking at the fall of Yoshida castle (Aichi prefecture) held by Makino clan and surrender of Toda clan at Tahara castle (Aichi prefecture) which were two major castles at east half of the province, Okudaira clan and Suganuma clan subordinated to Matsudaira clan, Kiyoyasu Matsudaira once united Mikawa province at that year, but was killed in the incident at siege of Moriyama castle (Aichi prefecture) at that year.

After the death of Kiyoyasu Matsudaira, Matsudaira clan lost its power and being suppressed by Imagawa clan from eastward and Oda clan which was the lord of Owari province from westward. Imagawa clan and Oda clan fought for Mikawa province but Oda clan was broken at the battle of Azukizaka and Anjo castle (Aichi prefecture), then Matsudaira clan subordinated to Imagawa clan sending its successor Ieyasu Tokugawa as a hostage.

Following to Imagawa clan

Among such situation, Okudaira clan and Suganuma clan followed to Imagawa clan and were treated local lord of the area. In 1556 Sadakatsu Okudaira (1512-1595) who was the leader of Okudaira clan revolted against Imagawa clan, along with other local lord of Mikawa province. 

This attempt failed and Okudaira clan returned to the retainer of Imagawa clan, but this confusion delayed the expansion of Imagawa clan to Owari province and made time for Nobunaga Oda (1534-1582) to unite Owari province.

In 1560, Yoshimoto Imagawa (1521-1560) who was the leader of Imagawa clan marched to Owari province with large army, but faced sudden attack of Nobunaga Oda and died in the battle of Okehazama. Utilizing this situation Ieyasu Tokugawa left Imagawa clan and became an independent warlord of Okazaki castle (Aichi prefecture), then allied with Nobunaga Oda and fought against remaining Imagawa army at east part of province.

Change of masters

Ujizane Imagawa (1538-1615) who was the successor of Yoshimoto Imagawa could not send army to Mikawa province due to decline of Imagawa army and revolt at Totomi province (west part of Shizuoka prefecture), then Ieyasu Tokugawa pushed out Imagawa army from Mikawa province by 1565. 

However in 1568, Ieyasu Tokugawa broke with Shingen Takeda (1521-1573), the warlord of Kai province (Yamanashi prefecture) and once cooperatively ruined Imagawa clan. In 1570 Takeda army intruded into Mino province (Gifu prefecture) which was the territory of Nobunaga Oda, then Ieyasu Tokugawa sent Okudaira clan and Suganuma clan as a reinforcement army to Nobunaga. 

But Oda army was broken by Takeda army then Okudaira army and Suganuma army retreated. Looking at the strength of Takeda army, Okudaira clan, Damine Suganuma clan and Nagashino Suganuma clan turned to Takeda clan around 1571. As a front line of Takeda army toward Tokugawa territory, Takeda clan built Furumiya castle (Aichi prefecture) just at the north of Kameyama castle as their own camp, and Kameyama castle itself might be improved at this time.

Structure of Kameyama castle

Central area of Kameyama castle is an oblong shaped one of 60 meter long and 30 meter wide, wholly surrounded by clay wall and has gates at the middle of east line and west line. At the east of central area, there is a secondary area of 30 meter long and 30 meter wide, which is also surrounded by clan wall and has a gate at eastward and southward. This secondary area works as a gate area before central area.

As the southern slope of the hill is gentle compared with north slope, southward of central area and secondary area is covered by wide dry moat of about 20 meter width and line of clay wall. Contrary to this, north slope has only corridor area connects east edge and south edge of the hill.

Westward of central area might be a main gate of the castle, which is protected by a combination of small terraces and line of dry moats. Eastward of secondary area might be a backside gate and also has a combination of small terraces and dry moats. Except for a large central area there is no plenty space, then this castle might be used for military purpose and not for living.

Stubmling of Takeda army after loss of leader

In 1572 Shingen Takeda started westward campaign toward Oda clan and Tokugawa clan, then intruded into Totomi province and broke Tokugawa army at the battle of Mikatagahara. Next year Takeda army attacked Noda castle in which Noda Suganuma clan still resisted against Takeda clan, then fell it after one month siege. But Shingen Takeda fell in ill at the siege and died, then Takeda army gave up campaign and returned to Kai province.

Katsuyori Takeda (1546-1582), the fourth son of Shingen, became the successor of Shingen and continued the confrontation toward Oda clan and Tokugawa clan. But utilizing the return of Takeda army, Nobunaga Oda who was once forced to the corner expelled Yoshiaki Ashikaga (1537-1597) who was the 15th Shogun of Muromachi Shogunate and formed anti-Nobunaga alliance from Kyoto city, and ruined his enemy Asakura clan and Azai clan only in one month.

At the same time, Ieyasu Tokugawa started counter attack to Takeda army and encircled Nagashino castle which could separate his territory Mikawa province and Totomi province. Masasada Suganuma (?-?) who was the leader of Nagashino Suganuma clan stood for one month but opened the castle to Tokugawa army before arrival of reinforcement army of Takeda clan.

Estrange of marginal lord

Ieyasu Tokugawa also proposed Okudaira clan and Suganuma clan to leave from Takeda clan. Fall of Nagashino castle worsened the situation of Okudaira clan, and Okudaira clan was suspected for connection with Ieyasu Tokugawa. Looking at the collapse of anti-Nobunaga alliance, finally Sadayoshi Okudaira (1537-1599), the leader of Okudaira clan, left Kameyama castle and exiled to Ieyasu Tokugawa.

Ieyasu Tokugawa promised with Sadayoshi Okudaira an increase of territory and marriage of his daughter with Nobumasa Okudaira (1555-1615), son of Sadayoshi Okudaira, and placed Sadayoshi Okudaira as the commander of Nagashino castle. On the other hand, second son of Sadayoshi Okudaira kept at Takeda army as a hostage was executed. 

Looking at the loss of Nagashino castle, Katsuyori Takeda once gave up the attack to Tokugawa army and kept Kameyama castle as a front line toward Takeda army. Katsuyori processed succession of the leader of Takeda clan, and reorganized Takeda army preparing for next campaign toward Oda army and Tokugawa army during 1573. On the other hand, Sadayoshi Okudaira had to cope with expected attack of Takeda army to Nagashino castle with small force, and there was no room to be forgiven by Takeda clan again.

Afterward of castle

In 1575, Katsuyori Takeda attacked Nagashino castle but Nobumasa Okudaira (1555-1615), son of Sadayoshi Okudaira who protected the castle stood against fierce attack of Takeda army. Oda and Tokugawa army came to rescue Nagashino castle thoroughly broke Takeda army at the battle of Nagashino, and Takeda army retreated from Mikawa province after the battle.

As promised, Nobumasa Okudaira increased his territory and married with the daughter of Ieyasu Tokugawa. Nobumasa newly built Shinshiro castle (Aichi prefecture) at the downstream of Toyo-kawa river, and moved to Kanto region in 1590 along with Ieyasu Tokugawa. Tadaakira Matsudaira (1583-1644), son of Nobumasa Okudaira, once returned as the commander of Kameyama castle after the battle of Sekigahara in 1600, but moved to Ise Kameyama castle (Mie prefecture) in 1610 then Kameyama castle was abolished at this time.

Today no building remains but structure of the castle well remain on the hill. Not so large castle but thick clay wall and wide dry moat probably built breaking residential space well shows strong involvement of Takeda army. Together with technical structure of neighbor Furumiya castle, and huge dry moat of Nagashino castle, it shows total war of Takeda army and Tokugawa army held at the territory of small local lord and fates of lords involved in this disaster.


30 minutes drive from Shin-Tomei Expressway Shinshiro interchange to parking at tourist station “Tsukude Tezukuri-Mura”

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Pictures (click to enlarge)