23.Odawara Castle Part1

Odawara was supposed to be the capital of five generations of the Hojo Clan. The city is now supposed to be a popular tourist spot near Hakone hot spring. Odawara Castle first started as a small one in a new post town. The castle eventually grew under the rules of the Hojo Clan to one of the greatest castles during the Sengoku Period. It was finally turned into an important castle at the western edge of the Kanto Region during the Edo Period. The castle was located at the same place through all its life while it changed a lot, which is a very rare case. This article will focus on the history of the castle until the Sengoku Period.

Odawara was supposed to be the main castle for the five generations of the Hojo Clan. The city is now supposed to be a popular tourist spot near Hakone hot spring. Odawara Castle first started as a small one in a new transportation hub. The castle eventually grew under the rules of the Hojo Clan to one of the greatest castles during the Sengoku Period. It was finally turned into an important castle at the western edge of the Kanto Region during the Edo Period. The castle was located at the same place through all its life while it changed a lot, which is a very rare case. This article will focus on the history of the castle until the demise of The Hojo Clan during the Sengoku Period.

The current Odawara Castle, this main tower was rebuilt according to that during the Edo Period

Location and History (until Sengoku Period)

Beginning of the Castle and the Appearance of Sozui Ise

In the ancient time, passengers, who went to the Kanto Region from western Japan, didn’t often use the Hakone Route, but used the Ashigara Route instead. However, they eventually used the Hakone Route when some shrines near the route became more popular. Odawara was first formed as a transportation hub for the passengers not later than the 14th Century. On the other hand, Odawara Castle was thought to be built in the middle of the 15th Century. The Omori Clan, the first lord of the castle, built it in order to collect taxes from the passengers. For this reason, the castle was still small during its early stage.

The location of the castle

As for the location of the castle, it was said that it was first situated at Hachimanyama old enclosure, which is the north of the current Odawara Castle, and further away from the transportation hub. Considering the purpose of the castle, it may have been at the same place as the current one, or at Tenjinyama Hill, closer to the town.

The Hachimanyama old enclosure
The current Tenjinyama Hill

In the beginning of the Sengoku Period, a man named Sozui Ise, became one of the biggest heroes at that time, and later would become a legend. According to the legend, he started only as a Ronin, but eventually became a great warlord, through his own excellent talent. This has been recognized as a big success story of “Gekokujo” which means “giant killer”. However, in recent studies, it was discovered that he was originally a shogunal military guard called Moritoki Ise. He went to Sunpu, which is the current Shizuoka City, to help his sister who was in a dispute about the succession. She was the wife of the Imagawa Clan’s previous lord and wanted her son to be the successor but had to compete with another candidate.

A copy of the portrait of Sozui Ise, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)

Sozui (Moritoki) succeeded in the son’s victory. He got Kokokuji Castle as an award of his contribution, which was the beginning of his real success story. The legend also says that Sozui drove the Omori Clan, which was the lord family of Odawara Castle, out from the castle, by tactics known as “Kagyu-no-kei”. Kagyu-no-kei refers to attacking enemies’ bases by using cows with lit torches on their horns. It was said that the statics had been done since the start of ancient China. However, the recent studies argue that it’s not that simple. According to a historical record, Sozui’s brother and the Omori Clan were actually on the same side at Odawara Castle and were defeated by the Uesugi Clan. Historians speculate that Sozui got Odawara Castle when they became enemies, or the castle was damaged because of a huge earthquake around 1500. Sozui was probably not only a hero, but also a practical man and a good negotiator. The castle was still a branch castle even after Sozui got it.

The ruins of Kokokuji Castle
The statue of Sozui at Odawara Station, attacking by Kagyu-no-kei

Improvement of the Castle by Ujitsuna and Ujiyasu Hojo

Sozui’s successor was his son, Ujitsuna Hojo, who was the second generation of the Hojo Clan. However, Ujitsuna was the person who changed his family name from Ise to Hojo. Therefore, Sozui Ise’s well-known alternate name Soun Hojo did not exist while he was alive. Soun was his Dharma name (this is the name given after the person dies). The reason for the change of the family name would be to go against the authority of the Uesugi Clan, the Hojo’s enemy. The Uesugi Clan looked down on the Hojo Clan because they were outlaws from another province. The Hojo Clan needed to improve their own authority in order to attract the local lords by using their new family name. “Hojo” had been the family name of the vice-Shoguns during the Kamakura Shogunate. Ujitsuna also moved his clan’s home to Odawara Castle.

The portrait of Ujitsuna Hojo, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)

Ujitsuna’s son, Ujiyasu Hojo was the third generation of the clan. He managed to increase the clan’s territories in the southern Kanto Region, particularly after the victory of the battle of Kawagoe Castle against the Uesugi Clan in 1546. Odawara Castle and its town were becoming the center of the region. The original small transportation hub was turned into the castle town, being as large as that during the Edo Period. The Odawara Water Supply System was installed in the castle and the town. It is said to be one of the earliest water supply systems in Japan. As for the castle itself, the main portion of the castle was built, such as the current main and second enclosures. A priest, who visited Odawara Castle in 1551, recorded that there was a large pond surrounding the castle in three different directions. Part of the pond remains as the moat of the current second enclosure.

A copy of the portrait of Ujiyasu Hojo, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)
The current Odawara Water Supply System
The moat of the current second enclosure

The first big crisis happened to Odawara Castle in 1561. Kenshin Uesugi invaded the Kanto Region from his home of Echigo Province, which is currently Nigata Prefecture, in order to revive his clan. Kenshin sieged Odawara Castle with his allies and over 100 thousand soldiers the following February (according to the luna calendar). However, the attackers withdrew soon as they did not prepare for a long siege. Ujiyasu Hojo, who was the lord of the clan, avoided fighting against Kenshin but waited patiently for the withdrawal. After Kenshin went back to his home, Ujiyasu got the territories and the retainers in the region back to the same side.

The portrait of Kenshin Uesugi, owned by the Uesugi Shrine (licensed under Public Domain via Wikimedia Commons)

The second crisis occurred in October 1569 (according to the luna calendar). Shingen Takeda from Kai Province, which is currently Yamanashi Prefecture, invaded the Hojo’s territories and reached Odawara Castle on the 1st of October. Shingen first attacked the main gate, called Hasuike-mon (which means lotus-pond gate), and set the castle town on fire. Shingen’s troops also torched the hall of Ujimasa Hojo, Ujiyasu’s successor. Shingen stayed at Odawara for only five days and returned to his home. However, these two crises had a big impact on the Hojo Clan, especially on Ujimasa. When he followed his father’s position, he started to fortify Odawara Castle more and more. He probably thought that if he could build a castle that could withstand a long siege, no enemies would ever destroy it.

The portrait of Shingen Takeda, owned by Jimyo-in, in the 16th century (licensed under Public Domain via Wikimedia Commons)
The portrait of Ujimasa Hojo, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)
Goyomai Enclosure, where Ujimasa’s hall was built

Completion of the Castle by Ujimasa and Ujinao Hojo

The Hojo Clan reached its peak in the period of Ujimasa and his successor, Ujinao. This was because Kenshin died in 1578 and the power of the Takeda Clan decreased. The Hojo ruled most of the Kanto Region and built the network of their branch castles to maintain their government. Odawara Castle became the center of it. Ujimasa also fortified the castle. For example, the third enclosure was built on a plain land around the second enclosure. After that, the outer third enclosure was also built on a hill behind the main portion of the castle. They were constructed to protect the castle from potential enemies attacking it from the front and from the back. Furthermore, a large ditch was built to separate the highest hill around the castle, called Komine-Okane-no-dai, next to the outer third enclosure. All of them were made using soil. It was dug to create very steep moats and was mounded to make high earthen walls. The soil around the area came from volcanic ash, which is called Kanto loam layer. It’s naturally slimy, which made enemies slipped when they walk on the surface. The bottoms of the moats were also partitioned forming many square partitions, called Shoji-bori (which means sliding paper door-moat) and Une-bori (which means hilling-moat). If enemies fell to the bottom, they would be trapped and would never be able to escape from it.

The portrait of Ujinao Hojo, owned by Hounji Temple (licensed under Public Domain via Wikimedia Commons)
The outer third enclosure
The large ditch at Komine-Okane-no-dai Hill
The Shoji-bori system in Yamanaka Castle

The development of the castle was related to the situation of the whole country and the diplomatic relations with other warlords. When Nobunaga Oda defeated the Takeda Clan in 1582, the Hojo was forced to be subordinate to Nobunaga. However, Nobunaga was killed during the Honnoji Incident in the same year. The Hojo, Tokugawa, Uesugi Clans battled each other in order to get the former territory of the Takeda Clan. A retainer of the Takeda Clan, the Sanada Clan gained power in order to be an independent lord by interrupting them. As time passed, Hideyoshi Toyotomi became the next ruler, ordering all the lords to stop fighting for themselves. Ujimasa ignored this new movement while other lords followed Hideyoshi by 1587. Ujimasa started a negotiation to serve the Hideyoshi side as well as the following year. One of the problems for the negotiation was about the Numata territory. There has been a dispute as to who was the true owner of the territory, between The Hojo Clan and Sanda Clan. Ujimasa asked Hideyoshi to resolve it. Hideyoshi’s decision was to give two thirds of the territory to the Hojo Clan and the other third to the Sanada Clan.

The portrait of Nobunaga Oda, attributed to Soshu Kano, owned by Chokoji Temple, in the late 16th century (licensed under Public Domain via Wikimedia Commons)
The portrait of Masayuki Sanada, privately owned (licensed under Public Domain, via Wikimedia Commons)
The Portrait of Ieyasu Tokugawa, attributed to Tanyu Kano, owned by Osaka Castle Museum (licensed under Public Domain via Wikimedia Commons)
The Portrait of Hideyoshi Toyotomi, attributed to Mitsunobu Kano, owned by Kodaiji Temple (licensed under Public Domain via Wikimedia Commons)

On the other hand, Ujimasa continued to fortify Odawara Castle in case the negotiations broke down. The highlight of it was to surround the entire area of Odawara including the castle, the town and the hills behind them. This was done by building moats and earthen walls, whose perimeter was about 9km long. This structure is generally called So-gamae (which means outermost enclosure). Ujimasa probably thought that enemies would never enter Odawara, because of this long perimeter, called So-gamae structure.

The red line shows the estimated line of So-gamae structure

The imaginary drawing of the So-gamae structure, from the signboard at the site

In October of 1589 (according to the luna calendar), an incident happened at the Numata territory. The Sanada Clan argued to Hideyoshi that the Hojo Clan forcibly got Nagurumi Castle on the Sanada’s side. This angered Hideyoshi and he finally decided to destroy the Hojo Clan completely. However, there are several questionable points about the incident. Some historians point out that It might have come from a deception of Hideyoshi and the Sanada Clan. Anyway, the battle between them may have been necessary. Hideyoshi wanted more territories to give to his retainers while Ujimasa didn’t want to surrender to Hideyoshi so easily. The So-gamae structure was eventually completed after the two-year constructions before the battle would happen.

The ruins of Nagurumi Castle

Battle of Odawara

In March of 1590 (according to the luna calendar), about 220,000 of soldiers, led by Hideyoshi Toyotomi, rushed into the Hojo’s territories. The number of the Hojo’s defenders was said to be about 80,000. About 50,000 of them were in Odawara Castle. The Hojo Clan probably expected that their enemies would be weakened by the network of the Hojo’s branch castles before they reached Odawara Castle. If they sieged the castle in poor conditions, the Hojo Clan could make peace with them in better conditions. However, most of the Hojo’s soldiers were drafted farmers, nor were they experienced, nor were they trained, and nor were they motivated. The battles occurred on the 28th of March at Matsuida Castle in Kozuke Province (which is currently Gunma Prefecture), and on the 29th at Yamanaka and Nirayama Castles near Odawara. Surprisingly, Yamanaka Castle, which had strong defensive systems like Shoji-bori, was captured in less than one day by the overwhelmingly powerful military force of the Toyotomi side. After that, the castles’ network of the Hojo side eventually collapsed. As a result, only 5 out of tens of the branch castles survived at the end of May. That was the first miscalculation for the Hojo Clan.

The network system of the Hojo’s castles, from the signboard at the site

The Toyotomi’s troops reached Odawara Castle as early as in the beginning of April, surrounding the castle with about 180,000 soldiers. Hideyoshi launched the construction of his new stronghold, which would be called Ishigakiyama Castle, within the month. However, even with huge troops, they were not able to enter the castle, because they were blocked by the So-gamae structure. The structure was 30m wide at max and over 10m deep, with its slope at over 50 degrees. On the other hand, the Hojo side also miscalculated the features of the Toyotomi’s troops. Many of them were professionals and were equipped with enough supply systems. That meant they could survive in their battlefield for a very long time. They reached a much higher level in the combat than those of the Uesugi and Takeda Clans earlier on. As a result, the attackers and the defenders faced each other across the So-gamae structure in April and May.

The war map of Odawara Castle, from the signboard at the site

On the 5th of June, Masamune Date, who was the greatest warlord of the Tohoku Region, arrived at Odawara to serve Hideyoshi. That made the Hojo Clan know that no supporters would help them. The negotiation between the Toyotomi and Hojo sides started behind the scenes. Ujimasa’s successor, Ujinao Hojo was in charge of it. In Japanese, there is a figurative expression called “Odawara Hyojo” which means an inconclusive long conference. People generally think the Hojo didn’t know what to do during the siege. The fact might have been different from it. As time passed, four of the five surviving branch castles were captured in June. Only Oshi Castle was bearing being sieged by the Toyotomi troops like Odawara Castle. Ishigakiyama Castle, which had great stone walls, was completed on the 26th of June as Hideyoshi’s stronghold. Its appearance may have threatened the defenders of Odawara Castle, just a few kilometers away from it.

The portrait of Masamune Date owned by Sendai City Museum (licensed under Public Domain via Wikimedia Commons)
The ruins of Ishigakiyama Caslte

Ujinao finally surrendered to Hideyoshi on the 5th of July. It was said that the negotiation may have included a few territories reserved for the Hojo Clan. However, the decision of Hideyoshi, who completed his unification of Japan, was too strict to allow it. The four leaders of the Hojo side, including Ujimasa, were forced to do Harakiri. Even Ujinao, who made peace with Hideyoshi, was eventually expelled to Koyasan Temple. The Hojo Clan lost everything they had had. Some say that the decision had been planned from the beginning. The territorial allocation after the Battle of Odawara was as followed. Ieyasu Tokugawa moved from around the current Shizuoka Prefecture to the Kanto Region the Hojo Clan had had. Nobukatsu Oda, who was Nobunaga’s son but followed Hideyoshi, was also fired by Hideyoshi due to his rejection to move to Ieaysu’s previous territory. Hideyoshi gave the large vacant territories to his successor, Hidetsugu and his retainers. The satisfied retainers would monitor the actions of Ieyasu who was a potential enemy for Hideyoshi, killing two birds with one stone. In addition, the Sanada Clan got all of the Numata territory after the battle. Were they all coincidental?

The grave of Ujimasa Hojo, near Odawara Station

The Hojo Clan declined but Odawara Castle with the So-gamae structure was very effective against the attackers. For example, it was recorded that Kazuuji Nakamura, who owned Sunpu Castle, built So-gamae structure for his castle, too. In fact, Hideyoshi Toyotomi also built very long earthen walls to surround Kyoto, called O-doi, whose perimeter was about 23 km long. It was recently discovered that the walls had the Shoji-bori system. Hideyoshi also improved his home, Osaka Castle by building So-gamae structure from 1594. Some other lords, who joined the Battle of Odawara, built their own So-gamae as well, probably influenced by Odawara Castle.

The current Sunpu Castle
The restored stone walls of Osaka Castle, used in its So-gamae structure

To be continued in “Odawara Castle Part2”

128.Yogaiyama Castle Part3

More needs to be done to improve this historical site

Features

Strong defense in Back side

If you have time, you should check out the back side of the castle. This is because the ridge on the back is very narrow, so original trail and the ruins along it seem to remain as it was. The Main Enclosure and the enclosure behind it are divided by an artificial ditch to prevent enemies from attacking form the back. The ditch is partly supported by stone walls to avoid collapsing, which is rare in Japanese castles.

The ditch using stone walls divides the Main Enclosure and the back

The map around the castle

Moreover, two earthen lookout platforms are in line on the ridge at the back of these enclosures. They are also partly supported by stone walls or stone mound, which are also uncertain who built or improved it.

One of the lookout platforms
The stone walls supporting the platform
The trail gets thin between the platforms

The trail goes beside the platforms and between them, which was made thin cut by vertical moats both sides. That meant the defenders on the platforms would see and counterattack enemies easily.

The trail between the platforms
Looking up the platform from the thin trail
Overlooking the trail from the platform

Later History

In the Edo Period, a stone statue of the Takeda Fudoson or Acala, which worshiped Shingen Takeda, was built in an enclosure between the Gate Ruins No.2 and No.3. It has since been called the Fudo Enclosure. After the Meiji Restoration, the castle site continued to deteriorate, so local people built the stone monument of the birthplace of Shingen Takeda in 1929 to preserve them. The title of the monument was written by Heihachiro Togo, a famous admiral of the Japanese Imperial Navy. The castle ruins have been designated as a National Historic Site since 1991.

the Takeda Acala
The stone monument for the birthplace of Shingen Takeda at the Main Enclosure

My Impression

I recommend visiting both ruins of Yogaiyama Castle and Takeda Clan Hall at the same time because you will be able to see how the Takeda Clan protected their home base. They must have been like one castle or a set. On the other hand, let me ask one thing to Kofu City. In the ruins of Takeda Clan Hall, excavations and studies are often being done in recent years. However, why have the ruins of Yogaiyama Castle not been developed? More explanations is needed for historical fans at the site. Some parts of the ruins are covered with bushes. I hope in the future that the city will develop this mountain castle ruins as a set with Takeda Clan Hall.

The ruins of Takeda Clan Hall
A Masugata entrance of Takeda Clan Hall (The northern entrance of the Western Enclosure)
Excavations are ongoing at Takeda Clan Hall Ruins
A situation of Yogaiyama Castle Ruins

How to get There

I recommend using a car when you visit the castle ruins because there are few buses to visit them.
It is about a 20-minute drive away from Kofu-minami IC on the Chuo Expressway. There is a parking lot in front of the trail entrance to the castle ruins.
If you want to use public transportation, you can take the Yamanashi-Kotsu Bus bound for Sekisuiji Temple from JR Kofu Station and ride to the end. It takes about 15 minutes on foot from the bus stop to get the entrance.
To get to Kofu Station from Tokyo: Take the limited express Azusa or Kaiji at Shinjuku Station.

The parking lot in front of the trail entrance

That’s all. Thank you.
Back to “Yogaiyama Castle Part1”
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128.Yogaiyama Castle Part2

The spot for hikers and history fans

Features

Castle Ruins on Hiking course

Today, the ruins of Yogaiyama Castle are on a hiking course as well as a historical site in Kofu City. The top of the ruins on the mountain is about 250m above the starting point of the trail at the foot. Therefore, you need to prepare for a long hike or a grueling climb to visit the ruins, which takes over 30 minutes to reach the top. The first half of your tour will be a pure hike by climbing a natural zigzagging trail. You may see some stone walls along the route, but they were probably built after the castle period.

The entrance to the castle ruins
Were these stone walls built after the castle period?
The natural zigzagging trail

You will eventually find some signposts of Vertical Moat or Earthen Walls, which are around the entrance of the castle ruins. These actual ruins are partially covered with bushes, so you may not notice them without the signposts.

Around the entrance of the castle ruins
These ruins are partially covered with bushes

Original Gate Ruins along Trail

You will also find other ruins such as gates along the trail, however, the trail is not always on the original one. According to previous researches, the castle had 8 gates to reach the Main Enclosure on the top. As long as I checked, there are actually only 4 gate ruins with signposts along the current trail, which still look very defensive. I think they should be the original gates of No.2, No.3, No.6 and No.8.

The map around the castle

Getting close to the No.2 Gate Ruins
Here are the No.6 Gate Ruins

On the other hand, there are also other entrances of enclosures, which look like gate ruins without signposts. They are set straight in front of the enclosures, which mean not defensive, so may not be original and built later for hikers. If so, some original gate ruins (probably No.4, No.5 and No.7) are not on the current route probably because they are inconvenient for hikers.

This entrance seems to be not original

In addition, the No.1 gate ruins seem to be on the route, but without a signpost, which I didn’t notice.

I think this is around the N0.1 Gate Ruins as some stone walls remain

Who built Masugata System of this Castle?

Out of the 4 original gate ruins with signposts, No.2 (with the first signpost of Gate Ruins) and No.3 (with the second one) are so great. They are surrounded by stone walls, forming a square space, called Masugata. The trail also turns right to exit the gate, plus, other enclosures are in the back of the gate and ahead of the route. That meant the defenders would counterattack the front and side of the enemies in the Masugata.

The No.2 Gate Ruins, the trail turns right
The enclosure in the back of the gate
The enclosure ahead of the route.
The No.3 Gate Ruins, similar to the No.2 Gate Ruins
The trail turns right again

This structure is seen in other castles using high stone walls, which would be built much later than Yogaiyama Castle. However, it is not uncertain who built or improved this system. If the Takeda Clan built it, it would be very advanced, if Mitsuyasu Kato improved it, he would have applied it from other castles like Kofu Castle to Yogaiyama Castle.

The restored Yamanote-mon Gate of Kofu Castle which has the Masugata system
The miniature model of the Yamanote-mon Gate, exhibited in the Inari Turret of Kofu Castle

Main Enclosure, Largest one in Castle

The No.8 Gate Ruins are the entrance of the Main Enclosure. It is the largest enclosure in the castle on the top of the mountain, surrounded by thick earthen walls. There is only the stone monument for the birthplace of Shingen Takeda in it. There should be a good view point of Kofu city area, but unfortunately trees shut out the view.

The No.8 Gate Rums, the entrance of the Main Enclosure
The inside of the Mai Enclosure
The earthen walls surrounding the enclosure
The stone monument for the birthplace of Shingen Takeda
Unfortunately, this is not a good view point

To be continued in “Yogaiyama Castle Part3”
Back to “Yogaiyama Castle Part1”