Japan Castle Explorer: Tanba Kameyama Castle -Time to treason (13) now is time to treason-

Tanba Kameyama Castle

-Time to treason (13) now is time to treason-

Overview

Name: Tanba Kameyama castle (Tanba Kameyama-jo)
Alias:
Place: Aratsukacho Kameoka city, Kyoto
Type: Hill Castle
Built: 1579
Remaining remnants: Stone walls and moats
Title:

Brief History

Continued from Part 12

Tanba Kameyama castle (丹波亀山城, formal name is Kameyama castle but to distinguish from same name castle in Mie prefecture, it is often called as Tanba Kameyama castle) is located Kameyama hill at the river side terrace of Katsura-gawa river in the center of current Kameoka city..

Kameoka area is a small flat land places at 20 kilometer northwest of Kyoto city, and directly connected to Kyoto city by Kizugawa river. Due to its geographical condition, Kameoka area is an entrance from Sanin area to Kyoto city, and along with Yamazaki area which was the gate from Sanyo region, and important point to guard Kyoto city from westward.

Reign of Tanba province

Tanba province to which Kameoka area belonged was roughly divided into four basins, it mean Kameoka basin at southeast, Sasayama basin at southwest, Hikami basin at northwest and Fukuchiyama basin at north. Among them Kameoka basin is just the next of capital Kyoto city and has largest flat area, Kameyama area had been the center of Tanba province from ancient era.

During Muromachi era, Tanba province had been the territory of Hosokawa clan, the relative and highest class retainer of Muromachi Shogunate. Hosokawa clan placed their retainer Naito clan as deputy governor of the province, and Naito clan resided at Yagi castle in the north part of the basin and governed the province.

But because of the geographic condition of the province being separated into basins, local lords of other basin such as Hatano clan at Sasayama basin or Akai clan at Hikami basin did not follow to Naito clan. In the former half of 16th century, Naito clan was once defeated before Hatano clan and lost the reign of Tanba province.

Military base of MItsuhide Akechi

In the middle part of 16th century, Naito clan which accepted Nagayori Naito (?-1565), an important retainer of central ruler Miyoshi clan and elder brother of Hisahide Matsunaga (1510-1577), once broke Hatano clan and once seized the whole part of the province. But along with the decline of Miyoshi clan, Nagayori died in the battle against the alliance of Hatano clan and Akai clan then Naito clan fell into small lord of Kameoka basin again.

In 1575, Mitsuhide Akechi (1528-1582), a general of central ruler Nobunaga Oda (1534-1582), entered Tanba province to capture it. Mitsuhide once gathered local lords of the province other than Akai clan then attacked Kuroi castle, the main base of Akai clan, but faced betrayal of Hatano clan then suffered severe defeat and once retreated.

Considering this defeat, Mitsuhide took more careful strategy to fall castles one by one. Mitsuhide at first captured south half of Kameoka basin, and newly built Tanba Kameyama castle as his main base. At the same time Mitsuhide processed the siege of Hatano clan and Akai clan, and in 1579 ruined two clans then captured whole part of the province. Mitsuhide became the lord of Tanba province under Nobunaga thus Tanba Kameyama castle became the place of governance of the province.

Structure of Tanba Kameyama castle

Tanba Kameyama castle was built utilizing hill of about 200 meter long at the edge of the river terrace. According to old picture, central area of the castle is a rectangular one of 100 meter long and 50 meter wide area having upper terrace and lower terrace. At the center of upper area there might be the main tower, originally might be two stories but later became fiver story white wall tower.

Surrounding central area, there are several area at east, south and west which are now used as the ground of shrines, halls and gardens. The east area might be original main gate of the castle but later south areas are added and became main gate. Northward of the castle was protected by side marsh now used as a park. And other direction also had water moat originally.

Outside of core areas, water moat and outer barrier which was about 800 meter long and 400 meter wide surrounds the whole part of the castle except the north, before Sanindo road. Tanba Kameyama castle was huge military base at front area compared with Sakamoto castle, the economic main base of Mitsuhide, and it is also compared with the relationship of Himeji castle (Hyogo prefecture) and Nagahama castle (Shiga prefecture) built by his colleague Hideyoshi Hashiba (1537-1598, later Hideyoshi Toyotomi).

Dead end of Mitsuhide a Oda clan

In 1580, along with the fall of Nobumori Sakuma (1528-1582), the commander of Kinki region who faced Ikko Ikki army at Ishiyama Honganji temple, Mitsuhide became the regional chancellor of capital area Kinki region. In addition to his own army, Hosokawa clan of Tango province (Kyogo prefecture) and Tsutsui clan at Yamato province (Nara prefecture) were attached to Mitsuhide, and military power and economic power of Mitsuhide was outstanding in Oda clan.

However, at this point Mitsuhide had no front line in charge. Western front facing Mouri clan was managed by Hideyoshi Hashiba who captured Tajima province and deprived the room from Mitsuhide. Shikoku island where Mitsuhide had relationship with local warlord Chosokabe clan was left to Nobutaka Oda (1558-1583), and Kyusyu region which was the next target might be captured by these two army.

Front of Eastern Japan was also managed by Kazumasu Takigawa (1525-1586) at Pacific Ocean side and Katsuie Shibata (1521-1583) at Sea of Japan side, and there was no front thus Mitsuhide’s situation became a reserve army at capital. Army and economic power of Mitsuhide at critical area was a first target of restructuring after approaching unification of Japan by Nobunaga, like his predecessor.

Operation toward Mouri clan

In early spring of 1582, Nobunaga ruined Katsuyori Takeda (1546-1582), the warlord of Kai province (Yamanashi prefecture) and successor of Shingen Takeda (1521-1573), only in one month. Ieyasu Takeda (1546-1614), who was a lord of Mikawa province (eastern half of Aichi prefecture) and smaller ally of Nobinaga, faced against superior Takeda clan over 10 years and guarded the backward of Nobunaga.

To reward the achievement of Ieyasu, Nobunaga invited Ieyasu as a special guest to his main base Azuchi castle (Shiga prefecture) in the middle of pay. As a chancellor of capital area, Mitsuhide was order to make a reception of Ieyasu who visited Azuchi castle with small guard. It is a tale that Mitsuhide made a fault at this reception and was abused by Nobunaga, but authenticity of this tale is low.

At the same time, Hideyoshi Hashiba who faced Mouri army at western front encircled Bicchu Takamatsu castle (Okayama prefecture) by flood attack. As this castle was final defense line of Mouri clan to protect their core territory, Terumoto Mouri (1553-1615) , the leader of Mouri clan, came to the castle with his two uncles Motoharu Kikkawa (1530-1586) and Takakage Kobayakawa (1533-1597) and all Mouri army to rescue Bicchu Takamatsu castle.

Time to treason is now

Looking at this situation, Hideyoshi planned to ruin Mouri clan at one time battle thus asked reinforcements to Nobunaga. Nobunaga accepted the plan of Hideyoshi, then ordered Mitsuhide to depart to Chugoku region ahead of Nobunaga, then Nobunaga himself later do so. Mitsuhide returned to his military main base Tanba Kameyama castle to organize his army.

In the end of May, before his departure, Mitsuhide had a Japanese poem party with his acquaint nobles and priests at Atago Shrine. At this party Mitsuhide made a poem that meaning is “The time (to treason) is now. It is May of the season when rain (reign) falls”, which is interpreted as his expression of the will to treason against Nobunaga.

At the same time, Nobunaga left his guard at Azuchi castle for preparation and moved to Kyoto city with small guard. At the same time, Nobunada Oda (1555-1582), the successor of Nobunaga, also stayed at Honnoji temple of Kyoto city only with small guard. The reason of this stay is not clear but at this time Ieyasu who left Azuchi castle toured Kyoto and Osaka area, then Nobunaga might plan to accompany that.

Process and complete of coup d'etat

As a chancellor of Kinki region, Mitsuhide knew this situation and identified a chance of lifetime. On July 1, Mitsuhide departed Tanba Kameyama castle with his army to pretend to move to western front, but turned his army to Kyoto city crossing Oinosaka pass at the border of Kyoto city and Tanba province. In the early morning of next day Mitsuhide assaulted Nobunaga stayed Honnoji temple.

According to Shincho Koki, an official biography of Nobunaga Oda, Nobunaga at first there was a quarrel between soldiers, but later knew this was the revolt by Mitsuhide, Nobunaga told "We have to accept" . Nobunaga resisted to dominant Akechi army with bow and spear for a while, but later being wounded Nobunaga entered inside the building and killed himself. Nobunaga ordered to burn down the build, thus the body of Nobunaga was not discovered.

Akechi army that ruined Nobunaga next attacked Nobutaga Oda at Myokakuji temple. There was a possibility of escape, but fearing the fate at being captured, Nobutada moved to the nearest residence of prince and besieged. But finally being outnumbered by Akechi army, Nobutada and his generals all died in the residence.

Only Nobutada's son Sanposhi (1580-1605, later Hidenobu Oda) was lead by Nobutada’s retainer Geni Maeda (1529-16t02) and left Kyoto city then survived. Now most famous coup d'etat in Japanese history was accomplished, and Nobunaga died just before the unification of Japan. This is called as "Honnoji no Hen" (incident of Honnoji").

Cause of incident

From past to now, many person discuss about the cause of this coup d'etat, and there might be a multiple cause and Mitsuhide made a comprehensive judgment. Consider the cause with a framework of "fraud triangle" for accounting and internal control which means that fraud occurs when these three conditions allows, it mean opportunity, pressure (necessity) and justification.

Opportunity is relatively clear. Around this period, major part of soldiers and generals faced enemy at each front, and there was a military vacuum around Kyoto area except for the army of Mitsuhide. Nobunaga originally grew his guard named Horoshu, but along with the expansion of territory these guards promoted to generals and were allocated to the castles.

Especially occupation of former Takeda territory required many generals as Nobunaga killed most part of Takeda generals, thus Nobunaga placed many veteran generals and soldiers to the occupied area. It is said that Nobunaga planned to grew next guard from local lords of Omi province (Shiga prefecture), but this was just started and still on the process.

Furthermore, both of Nobunaga and his successor Nobutaga stayed at same place with only small number of soldiers thus it was a extraordinary opportunity to destruct the government only one time attack. It was an inexcusable matter from the perspective of crisis management.

Next is pressure or necessity. Historically the following matters are discussed as a necessity of coup d'etat;

1) Personal grudge against Nobunaga, such as continuous scolding for failure or death of Mitsuhide's mother at Yagami castle when Nobunaga broke the agreement to save Hatano clan
2) Mitsuhide's fear for future territory transfer or purge same as his predecessor Nobumori Sakuma, considering too much army stayed as reserve
3) Order?from the Imperial Household, to prevent Nobunaga to become a new emperor
4) Order of ex shogun Yoshiaki to the former retainer Mitsuhide
5) Plot by other large retainer of Nobunaga, such as Ieyasu Tokugawa or Hideyoshi Hashiba (Toyotomi) who feared future purge　from Nobunaga after the unification of Japan
6) Change of diplomatic policy against Chosokabe clan in Shikoku island as mentioned above. Mitsuhide who lost face tried to keep friendship with Chosokabe clan, or Chosokabe clan faced excursion of Oda army urged Mitsuhide to revolt
7) Just as a talented and ambitions general, Mitsuhide utilized best opportunity to become the ruler

Finally regarding to the Justification, to oppose to the innovation of Nobunaga, Mitsuhide had to insist the continuation of traditional tradition such as Muromachi Shogunate or Imperial Household. This was useful to attract nobles in Kyoto city, but Mitsuhide himself was already hostile to such traditional power and it did not work to gather other generals, and probably to raise Mitsuhide himself.

Mitsuhide did not clarify the reason of coup d'etat and died just after that, thus the precise reason is still not clarified. The reason might be a complex, but one was surely the fault and carelessness of Nobunaga, and another might be the dead-end status of Mitsuhide at Oda clan finally fixed by the change of diplomatic policy..

Change of holders

Mitsuhide once seized hegemony at central area but was defeated by Hideyoshi Hashiba quickly returned from western front at the battle of Yamazaki and died only after 10 days from coup d’etat. Soon after that Tanba Kameyama castle was attacked by Hashiba army, and the son of Mitsuhide stayed at the castle died there.

After the death of Mitsuhide, Tanba Kameyama castle was still quite important castle for the rulers to protect Kyoto city. Hideyoshi Toyotomi who became next ruler placed his relative or trustable generals at Tanba Kameyama castle, such as Hidekatsu Hashiba (1569-1586) or Geni Maeda who became one of five magistrates of Toyotomi government.

Ieyasu Tokugawa who established Edo Shogunate after the death of Hideyoshi also thought important of this castle, ordered an excellent castle builder Takatora Todo (1556-1630) to renovate this castle into a modern one with five story tower style main tower.

Afterward of castle

Tanba Kameyama castle was kept by hereditary retainers of Edo Shogunate until the end of Edo era, but subsequent to Meiji revolution the castle was abolished. In 1920's a religious organization named "Ohmoto" bought the castle site as their main temple, but this organization was thoroughly suppressed by the government and the ruin of the castle was destroyed by the government.

After World War 2, castle site was returned to the organization and now used as their main temple. A magnificent main tower base was restored, but entrance is prohibited to religious reason. The shape of the castle is barely kept at the hill, and outer moat of the castle still remain at the backside of the hill and used as a park. Quiet ruin of the castle is a suitable place to think cause of the incident performed by the builder.

Continue to Part 14

Pictures (click to enlarge)

Important Notice:

Site of Tanba Kameyama castle is used as a sacred place of religious organization "Ohmoto", and to enter the former central area it is necessary to be purified by their priest. It is only just simple purification without any charge, but to avoid trouble it is strongly recommended to visit with Japanese (inside of main tower basement is off limit).