20.Sakura Castle Part1

Sakura Castle was located at the current Sakkura City of Chiba Prefecture. The castle was built as the home of the Sakura Domain during the Edo Period, which is the origin of the city. The areas around the city had many other castles until the Sengoku Period and some of which were very important.

Location and History

Sakura Castle was located at the current Sakura City of Chiba Prefecture. The castle was built as the home of the Sakura Domain during the Edo Period, which is the origin of the city. The areas around the city had many other castles until the Sengoku Period and some of which were very important. For example, there was Usui Castle in the western part of the city, where the battle of Usui Castle happened back in 1566. Kenshin Uesugi, who tried to rule the whole Kanto Region, attacked the castle but failed. There was also Motosakura Castle in the eastern part, which was the home of the Chiba Clan. Usui Castle was a branch of the clan. Cuttently, this castle is called “Motosakura” but back then, it was called “Sakura Castle”. So therefore, Sakura Castle was the former name of Motosakura Castle. This article will explain the formative years of Sakura Castle including the formation of Motosakura Castle, which should make it easier for people to better understand the history.

The ruins of Usui Castle, Notice the wooden log steps covered in soil
The ruins of Motosakura Castle, Notice the icon on the wooden shields.  This is the family crest of the Chiba Clan

Formative Years of Sakura Castle

The Chiba Clan had owned Shimosa Province, which was the northern part of Chiba Prefecture, since the end of the ancient times. The most famous person of the clan would be Tsunetane Chiba who supported the launch of the Kamakura Shogunate at the end of the 12th Century. Their home, Inohana Castle, was located at the current Chiba City for a long time. However, the castle was destroyed when many battles occurred in the 15th Century during the Sengoku Period. The clan decided to rebuild their new home in another location, which would be called Motosakura Castle. The castle was on the Shimosa plateau and was surrounded by Inbanuma Lake and other waterlogged areas. Its location was much more fortified than before and more convenient for water transportation. The lake was also much larger than now, where people could easily access Kasumigaura Lake and other great rivers. The wide water area was even called Katori-no-umi, which means the Katori inland sea.

The statue of Tsunetane Chiba, exhibited by Chiba City Folk Museum
The whole map of Motosakura Castle, from the signboard at the site

The situation changed during the 16th Century. The Hojo Clan was invading the Kanto Region from the west. On the other hand, the Satomi Clan also got the power from the south (Boso peninsula). The Chiba Clan wondered what to do and they eventually allied with the Hojo Clan. That’s why Kenshin Uesugi, who would help the Satomi Clan, decided to attack Usui Castle, a branch of the Chiba Clan. The victory of the clan was partially due to the Hojo Clan’s help. As a result, the Hojo became more effective to the Chiba Clan. As for the home of the clan, Chikatane Chiba, who was the lord of the clan before the battle, originally planned to move his home from Motosakura to another. The new land for his new home later became Sakura Castle, which was called Kashima Castle then. Mysteriously, he died in 1533, which ultimately canceled his plans of moving the castle.

The location of the castle, Notice the smaller Inbanuma Lake on the left next to Usui Castle. This important river used to span much larger that what the current map is showing. It used to be part of a much larger body of water.

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

The Hojo Clan interfered in the internal affairs of the Chiba Clan at the end of the 16th Century. For instance, Ujimasa Hojo married his daughter to Kunitane Chiba, the lord of the clan. The Hojo Clan allowed Kunitane to resume the construction of Kashima Castle but failed to do so because the lord was killed again. Ujimasa next married his son to Kunitane’s daughter, in order to be the successor of the clan. It was said that Kashima Castle was finally finished for the new home of the couple.

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

However, it is difficult to confirm whether these records are the factual, as Sakura Castle was built on the old Kashima Castle. The few discovered old dry moats at the site proved that they were at least trying to build the castle there. So, why did the Chiba and Hojo Clans want to move there again and again? One of the reasons would be that the land for the new castle was much larger than the old one. For the Hojo Clan, another possible reason may have been to protect their territories from the potential invasions by Hideyoshi Toyotomi from the west. The plateau, where the new castle was built on, had steep slopes and was surrounded by rivers towards the direction. That would have had a very defensive fort against the invasion. However, the Chiba Clan was eventually fired by Hideyoshi, after their master, the Hojo Clan was defeated at the battle of Odawara Castle in 1590.

The current Sakura Castle
The current Odawara Castle

Toshikatsu Doi builds Sakura Castle

After the Battle of Odawara Castle, several lords were assigned one after another by Ieyasu Tokugawa who was the founder of the Tokugawa Shogunate. In 1610, Ieyasu ordered his retainer, Toshikatsu Doi to stay in Motosakura Castle and to build a new home at the former location of Kashima Castle, which would eventually be called, Sakura Castle. The new castle was supposed to support Edo Castle, the home of the shogunate. If Edo Castle was attacked by enemies from the west, the shogun could escape from his home to Sakura Castle towards the east. Sakura Castlewas situated in a great location that had very strong natural defense.

The portrait of Toshikatsu Doi, owned by Jojoji Temple (licensed under Public Domain via Wikimedia Commons)

Toshikatsu served three generations of the shoguns: Ieyasu, Hidetada, and Iemitsu. He was one of the most important senior vassals for them and established the system of the government. He was born in 1573 when Ieyasu was only a warlord during the Seongoku Period. There are some theories about who his father was.
The first one is that Toshimasa Doi was his father, according to the official family trees by the shogunate.
The second one claims that he was a son of Nobumoto Mizuno who was a brother of Odai, Ieyasu’s mother, according to the official history books of the shogunate. Odai originally came from the Mizuno Clan.
The last theory is the most surprising theory, it was said that Toshikatsu was an illegitimate son of Ieyasu, according to the official trees of the Doi Clan.
Each theory has substantial evidence, however only one theory can be true. Why were there different theories?

The Portrait of Ieyasu Tokugawa, attributed to Tanyu Kano, owned by Osaka Castle Museum (licensed under Public Domain via Wikimedia Commons)

Recent studies believe the followings. Toshikatsu has a short sword where the family crest of the Mizuno Clan was engraved. It was passed down from Odai to Ieyasu who gave it to Toshikatsu. That meant Toshikatsu was Ieyasu’s son. However, it was a very know fact, which was not recorded officially. That’s why the official family trees simply say Toshikatsu was a biological son of the Doi Clan (in fact, adopted). After that, Toshimasu Doi, who was a grandson of Toshikatsu, was worried about the declining reputation of his clan. He thought that he should settle the mystery of his grandfather to gain a stable position for the clan. His decision was that he would announce that Toshikatsu was a son of the Mizuno Clan by using its family crest on the sword. The writers of the official history books probably heard about it. Finally, Toshisato Doi, the 8th lord of the clan, was asked as to who Toshikatsu’s mother was by the shogunate. Toshisato decided that he would answer by telling the truth and put it on his clan’s official trees. However, the shogunate couldn’t accept it because the matters of Ieyasu were too serious to change for them. As a result, the three theories certainly unchanged today. As for Toshikatsu himself, he became a close vassal of Hidetada, who was the successor of Ieyasu, when Toshikatsu was only 7 years old. No matter who his father was, it’s no mystery that he was a very talented person.

The portrait of Toshimasu Doi, owned by Jojoji Temple (licensed under Public Domain via Wikimedia Commons)

When Ieyasu established the shogunate, his most influential retainers were the Honda and the Okubo Clans. However, they often had internal conflicts with each other. As a result, Masazumi Honda survived when Hidetada became the 2nd shogun. Hidetada didn’t want to let Masazumi have more power. He and his close vassals, including Toshikatsu Doi, decided to trick Masazumi. When Masazumi went on a business trip from his home, Utsunomiya Castle, to another castle where he was told about his replacement. That’s the reason Masazumi would not be able to raise a rebellion. In fact, that’s the same way Masazumi excluded the Okubo Clan earlier on. Toshikatsu must have joined the careful planning of the strategy. He continued to serve the shoguns, including the third shogun, Iemitsu, for a long time. He also contributed to the shogunate by building the group guidance system of the shogunate. The system would avoid relying on individual abilities and having internal conflicts so much like the shogunate had used to.

The portrait of Masanobu Honda, owned by Kaga-Maeda Museum (licensed under Public Domain via Wikimedia Commons)
The portrait of Tadayo Okubo, owned by Odawara Castle (licensed under Public Domain via Wikimedia Commons)

In reality, Toshikatsu survived these internal conflicts. Therefore, people sometimes viewed him as a Machiavellian. On the other hand, he was a well-informed and kind person whom the shoguns, his colleagues, and even foreign merchants often relied on. That may be one of the reasons for his longevity. He was also the founder of the Sakura Domain and built Sakura Castle in over 7 years, which was eventually completed in 1616.

Features of Sakura Castle

Sakura Castle, which was built on a large plateau, had several distinctive features. First, the castle wisely used the natural shapes of the plateau. The plateau was basically a natural hazard, which was about 20m above the foot of the hill and surrounded by Takasaki and Kashima Rivers. The main enclosure was built at the western edge of the plateau, and other enclosures were built around it. Large dry moats and the main gate were also constructed to the east for fortification. The Samurai residences and the castle town with Narita Road were built over the gate. Overall, the castle and town were all created on the plateau.

The illustration of Sakura Castle in Shimousa Province, exhibited by the National Diet Library
The old photo of the main gate, from the signboard at the site, Notice how small the people are.  The gate was so much bigger compared to modern gates today
The remaining dry moat

Secondly, the castle foundations were all made from soil, not using stone walls. When the battle of Odawara Castle happened, Hideyoshi Toyotomi built a castle made of pure stone walls, called Ishigakiyama Castle, for the first time in the Kanto Region. Since then, similar castles, such as Edo Castle, were built in the region. However, Sakura Castle kept the traditional method of the region, using only soil. Other castle used the same method, such as Kawagoe and Utsunomiya Castles. On the other hand, the castle had some of the latest defensive systems at that time. There were two defensive positions, called Umadashi, in front of the gate of the third enclosure. There were also huge enclosures outside the third enclosure, which could accommodate lots of soldiers and was used as a parade ground. Furthermore, the belt enclosures were built on the slopes of the plateau where the defenders were able to move easily. Finally, the enclosures connected to two barbican enclosures outside the plateau.

The ruins of Ishigakiyama Castle
The main tower base of Sakura Castle, Notice that not one stone was used
The current Utsunomiya Castle
The Umadashi enclosure of Sakura Castle
The belt enclosure of Sakura Castle
The barbican enclosure of Sakura Castle, Notice the amount of algae covering the moat

The final feature is about the buildings of the castle. There was the main tower in the main enclosure, which was about 22m high and had three levels (four floors). It was extremely rare for that type of castle to be built at that time. (The shogunate basically didn’t allow new castle constructions after its rules were established.) The tower was said to have moved from Edo castle. Its details are unknown, however, because it was unfortunately burned down by an accidental fire during the Edo Period. Historians speculate that it was similar to that of Koga Castle, which Toshikatsu also built later on. There were also Do-yagura (Copper Turret) and Sumi-yagura (Corner Turret) in the main enclosure. The enclosure also had the main hall inside but was barely used. This was because it was once used by Ieyasu Tokugawa, so it was considered exclusive to the shoguns. Instead, the lord of the castle lived in the main hall of the second enclosure. Atter the hall deteriorated; a new hall was built outside the third enclosure.

The miniature model of the main tower, exhibited by Sakura Castle Park Information Center

Masayoshi Hotta comes up with an idea to Open the Country from Sakura Castle

After Toshikatsu Doi moved to the Koga Domain in 1633, several lord families ruled the Sakura Domain during the Edo Period. In particular, the Hotta Clan owed the domain and castle for a long time until the end of the period. I will describe Masayoshi Hotta who was one of the lords and how he devoted his life to reforming and opening the country to the rest of the world. Masayoshi was born in 1810 and became one of the core members of the central government when he was 32 years old. However, he quit the position 2 years later because he didn’t really get along with Tadakuni Mizuno, the top of the government under the shogun. However, he kept in touch with his colleagues like Masahiro Abe and Naosuke Ii.

Masayoshi Hotta (licensed under Public Domain via Wikimedia Commons)

He also reformed the government of the Sakura Domain. He declared the reform to the retainers of the domain at the main hall in the third enclosure of Sakura Castle. One idea was to include the military system of the domain. He changed it to the western style and he allowed the soldiers to exercise in the castle. Another major change from the reform was that Masayoshi introduced the western medicine to the domain. He invited a famous doctor, Taizen Sato from Edo City, who opened a medical school, called Sakura-Juntendo. Lots of students gathered there from all around Japan, which gave Sakura the name Rangaku (Dutch studies) town similar to Nagasaki. (At that time, the western science was provided from the Netherlands, one of the few countries which had diplomatic relationship with Japan.) Masayoshi was also called “Ranpeki” which means a person who devotes oneself entirely to Dutch studies and way of life. As a result, the scenery of Sakura Castle and the town dramatically changed.

Taizen Sato (licensed under Public Domain via Wikimedia Commons)

After the arrival of Matthew Perry’s fleet in 1853, Masahiro Abe, who was the top of the government, asked the country to vote on whether or not Japan should open the rest of the world. Despite Masayoshi’s wishes to open Japan, most people voted against it. Masayoshi was suddenly assigned the top of the government (the chief of the members of shogun’s council of elders) in 1855. However, the reason why Masayoshi was appointed the top official was still uncertain. One of his tasks was to negotiate with Townsend Harris, the council of the U.S. about the trade treaty. Masayoshi actively dealt with Harris because both of them really wanted Japan to open to the rest of the world. The treaty was still unfair, however. For example, Japan didn’t have autonomy to tariffs. On the other hand, Masayoshi decided to open Yokohama Port which would become a worldwide port even today.

The portrait of Masahiro Abe, owned by Fukuyama Seshikan High School (licensed under Public Domain via Wikimedia Commons)
Townsend Harris (licensed under Public Domain via Wikimedia Commons), An older picture of Townsend Harris

Even after the deal with Harris was finalized, Masayoshi still needed to handle a more difficult task. It was to get approval of the treaty from many relative lords in the government. When Toshikatsu Doi was the top, the system was simpler than the period of Masayoshi. However, the system had completely changed. The result was that only 4 of the 18 relative lords supported it. Therefore, Masayoshi’s second option was to get approval from the emperor, which had ever not been done. It would be the most effective way to overrule the lords. He visited the imperial court in Kyoto in 1558 to persuade the emperor and the nobles but he failed. This was because the emperor Komei himself did not want to open the country to the rest of the world.

The portrait of Naosuke Ii, owned by Hikone Castle Museum (licensed under Public Domain via Wikimedia Commons)

Masayoshi was unfortunately fired, and the matter of the treaty was contnued by Naosuke Ii. He went back to the hall of Sakura Castle and lived there until his retirement and until his death in 1864. After the Meiji Restoration, the castle was used as a base for the Japanese Imperial Army. The mission of the base was to guard the eastern areas of Tokyo, the new imperial capital and the former shogun’s capital. That meant the role of the castle was the same between the Edo Period and the Meiji Era. After World War II, it became Sakura Castle Park and part of the park is used as National Museum of Japanese Histories today. The location of the castle is very suitable for such a large museum.

The statue of Masayosho Hotta in the third enclosure of Sakura Castle
The miniature model of Sakura Castle when the Japanese Imperial Army used it, exhibited by the National Museum of Japanese Histories
The entrance of Sakura Castle Park
The entrance of National Museum of Japanese Histories

To be continued in “Sakura Castle Part2”

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”

114.Karasawayama Castle Part3

The stone walls of the main enclosure entrance are not so high, but use several huge ornament stones.
In addition, the entrance was recently researched and it was found that it had a turret gate. Overall, these structures made the castle stronger as well as more authorized.

Features

Great Stone Walls of Main Enclosure

The stone walls are around 8m high and about 40m long. They were built by piling natural or roughly processed stones in a way called Nozura-zumi. They look rough but really great! It was said that the last lord, Nobuyoshi Sano built them by inviting an excellent guild of stone craftsmen celled Ano-shu from western Japan.

The map around the castle

The high stone walls of the enclosure
The stone walls seen from the second enclosure side

You will eventually enter the second enclosure just below the main enclosure. Therefore, you will see the entrance of the main enclosure, which was also surrounded by great stone walls. They are not so high (at 2.5m), but use several huge ornament stones, called Kagami-ishi (meaning mirror stones).
In addition, the entrance was recently researched and it was found that it had a turret gate. Overall, these structures made the castle stronger as well as more authorized.

The second enclosure in the front and the main enclosure in the back
The entrance of the main enclosure
One of the ornament stones

The enclosure is on top of the mountain and is used for the shine buildings. It is unknown what buildings it had in the past, but it might have had buildings like the Main Hall and the Main Tower.

The front shrine hall
The stone walls around the enclosure

Defensive Spots in North and South

There is another enclosure, in the south of the main enclosure, called Nanjo (meaning southern castle). It was built to protect the southern ridge of the mountain where you can see stone walls and dry moats around. The shrine office is on the enclosure and this is another great viewing spot. If the weather is fine, you can enjoy a view of both Tokyo Sky Tree and Mt. Fuji. Nobuyoshi might have had no choice but to accept the shogunate’s close questioning that looking down on Edo Castle from the mountain would be rude.

The southern castle
The stone walls around the enclosure
The dry moats around the enclosure, called the First Moat
A view from the enclosure, it was clouded when I visited there

There is also other enclosures on the northern ridges, such as the Northern Castle. They are basically made of soil, divided by earthen ditches and connected by earthen bridges, which were older parts of the castle.

The Nagato-maru Enclosure
The Kane-no-maru Enclosure
The Sugi Enclosure
The double ditches between the Sugi and northern enclosures
The northern enclosure

Hiking Course has other Castle Ruins

For hikers, it is recommended to try part of Karasawayama Shuyu(Round) Course, from the castle to Imori-yama Mountain via the Kagami-iwa Rock, Byobu-iwa Rock and Gongen-do Hall Ruins. The course is on another ridge connected to the Karasawayama Mountain, which was a defense point for the castle.

The map around the mountain

The relief map around the mountain

The location map of the hiking course
The Kagami-iwa Rock
The byobu-iwa Rock and the view

That’s why you can see a set of a narrow bridge with artificial ditches on the way. You can also enjoy a great view of the whole Kanto Region on each peak of the ridge. The Imori Mountain is where Kenshin Uesugi and Masatsuna Sano fought against each other in their last battle in 1570.

The bridge over the ditch
Going to the Gongendo Hall Ruins
A view from the hall ruins
The zoomed Mt. Fuji
The top of the Imori Mountain

Later History

After the Sano Clan was banished by the Tokugawa Shogunate, the Ii Clan which was a senior vassal family of the shogunate owned the Sano area as its detached territory during the Edo Period. The clan banned people from entering the mountain, the former castle area. That’s why the ruins of the castle have been preserved in a good condition. After the Meiji Restoration, locals established the Karasawayama Shrine in 1883. Establishing shrines on castle ruins was a popular way to maintain them at that time. The ruins also became part of Karasawayama Prefectural Natural Park in 1965. That’s why several approaches and hiking courses have been developed there. As for castle ruins, Sano City has been researching and studying them since 2007. As a result, they were designated as a National Historic Site in 2014.

Karasawayama Shrine

My Impression

The current people often say Kenshin Uesugi attacked Karasawayama Castle and approached its main enclosure, but failed. Meanwhile, Kenshin himself wrote on his letter in 1567 when he owned the castle and was attacked by the Hojo Clan that “Only the Main Enclosure remained”. I’m not sure if similar things happened twice whether the people misunderstood Kenshin’s sides. Either way, Kenshin and the castle were closely involved. I think the people are still borrowing his name even today to explain about the strength of the castle.

The main enclosure of Karasawayama Castle

How to get There

If you want to visit the castle ruins by car, it is about a 10-minute drive away from Sano-Tanuma IC on the Kitakanto Expressway.
There are parking lots at the foot, the mid slope and top of the mountain.
By public transportation, it takes about 40 minutes on foot from Tanuma Station on the Tobu-Sano Line to the top.
From Tokyo to the station: take the train on the Joban Line from Tokyo or Ueno Stations, transfer to the Tobu-Isesaki Line at Kitasenju Station, and transfer to the Tobu-Sano Line at Tatebayashi Station.

The parking lot at the top
The parking lot at the southern route
The parking lot at the western route
The parking lot on the way of the hiking course

That’s all. Thank you.
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