Maruhakayama ancient burial mound – 日本200名城バイリンガル (Japan's top 200 castles and ruins)

Features

Ishida Bank

I recommend visiting some historical spots near the castle regarding the Battle of Oshi Castle. One of them is Ishida Bank Ruins, about 4km away from Oshi Castle Ruins in the southeastern direction. The bank is the nearly 300m remaining one out of the 28km banks Mitsunari Ishida originally built when the battle happened.

The map around the Ishida Bank

The monument of the bank, built at the end of the Edo Period

It goes along a river in the north and a road in the south, with some pine trees planted on it, which show it is an old road. The road was actually a byway of Nikko Road during the Edo Period and is said to have been on the major Nanasendo Road before the period.

The pine trees planted on the bank and the road in the south

The Horikiri-bashi Bridge over the river at the edge of the remaining bank is also said to be the place where the defenders of Oshi Castle cut and drained the water inside the bank against Mitsunari.

Sakitama Ancient Burial Mounds

Another recommendation is to visit the Sakitama Ancient Burial Mounds which were built between the 5th and 7th Centuries, much earlier than Oshi Castle, but some of them are related to it. Maruhakayama-Kofun or the Round Burial Mountain was one of them and the largest round burial mound in Japan, which is 17m high and its diameter is 105m. When the Battle of Oshi Castle happened, Mitsunari put his stronghold on the mound and instructed the bank construction. You can see the top of the rebuilt three-level turret of Oshi Castle from the top of the mound, where could have been a good place for Mitsunari to see the situation of the inundation tactics. The approach to the mound is also said to have been another Ishida Bank Ruins.

The aerial photo around the Sakitama Ancient Burial Mounds

The top area of the ancient burial mound

A view from the top of the direction of Oshi Castle

A view of the three-level turret, being zoomed in

In addition, Teppoyama-Kofun or the Gun Burial Mountain was involved in the history of the Oshi Domain at the end of the Edo Period. They cut one side of the mound to train their gunnery skill to prepare for their responsibility for protecting Shinagawa Batteries on Edo Bay.

The ground plan of the ancient burial mound, from the signboard at the site, the dark blue part was the training area

Later History

After the Meiji Restoration, Oshi Castle was abandoned and its water area was turned into a modern park with office buildings but being filled in. It could be needed for modernizing the city. The city was called Gyoda, named after the district which manufactured Japanese socks, Tabi and prospered.

An example of the Gyoda Tabi socks (*licensed by katorisi via Wikimedia Commons)*

The reproduced manufacturing site of Tabi, exhibited by the Gyoda City Local Museum

One of the remaining Tabi warehouses in the city

The park once had a baseball stadium, officials replaced it with Gyoda City Local Museum whose building looks like The Three-Level Turret the castle had. Some other buildings like a bell-tower, gates and walls were also restored around it, making them the city’s attractions.

The aerial photo around the Main Enclosure in the 1970’s

My Impression

The result of the Battle of Oshi Castle has been said to be the only failure of Hideyoshi Toyotomi during the invasion to the Kanto Region to complete his unification of Japan in 1590, which was blamed to Mitsunari Ishida who was a foolish general. However, I think the reputation comes from being wise after the event that Mitsunari was defeated by Ieyasu Tokugawa in the Battle of Sekigahara in 1600. It is not fair. Mitsunari was the faithful executor of Hideyoshi’s order in the battle, being successful in surrounding the castle. If the defenders were not instructed by Nagachika Narita, but a magistrate from the Hojo Clan, they might have soon surrendered to Mitsunari. I think the Battle of Oshi Castle was an excellent match where Nagachika and Mitsunari took on each other.

The family crest of the Narita Clan, called Maru-ni-mitsuhiki or Three horizonal lines inside a Circle, exhibited by the Gyoda City Local Museum

The Ishida Bank Ruins seen from the Horikiri-bashi Bridge

How to get There

If you want to go there by car, it is about 30 minutes from Kazo IC or Hanyu IC on the Tohoku Expressway. there are a few parking lots around the castle ruins. It may be better to use a car if you also want to visit Ishida Bank Ruins or the Sakitama Ancient Burial Mounds as well.
By public transportation, it takes about 15 minutes on foot from Gyodashi Station on Tobu line to get to the castle ruins.
From Tokyo to Gyodashi Station: Take the Joetsu Shinkansen super express and transfer to Tobu line at Kumagaya Station.

The parking lot of Gyoda City Local Museum with the monument of the Main Enclosure

That’s all. Thank you.
Back to “Oshi Castle Part1”
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Location and History

Narita Clan builds Castle using Marshes between rivers

Gyoda City is located in the northern part of Saitama Prefecture, which is sandwiched by two large rivers in the Kanto Region, Tonegawa and Aarakawa Rivers. The land of the city is very flat and has been developed for living comfortably, however, it was marshy and waterlogged in the Middle Ages due to its terrain and flood from the rivers. The Narita Clan governed the area, which was called Oshi, in the 15th and 16th Centuries during the Sengoku Period. It is said that the clan first built Oshi Castle in the late 15th Century. Many battles happened in the Kanto Region at that time, so local lords needed to protect themselves by building strong castles. Some built mountain castles such as Minowa Castle for the Nagano Clan and Kanayama Castle for the Iwamatsu Clan. On the other hand, the Narita Clan’s choice was to build a Water Castle, using the area’s features of islands among the marshes and natural levees along the rivers. The castle’s enclosures were connected by paths on bridges and earthen walls.

The range of Gyoda City and The location of the castle

The strength of the castle was actually proven when Hideyoshi Toyotomi invaded the Kanto Region to complete his unification of Japan in 1590. The whole region had been governed by the Hojo Clan which the Narita Clan served then. The Hojo Clan ordered their branches including Oshi Castle to gather soldiers to their home base, Odawara Castle to against Hideyoshi. Ujinaga Narita, the lord of Oshi Castle had to leave it for Odawawa, so few defenders were left in the castle, under the castle keeper, Nagachika Narita, Ujinaga’s cousin. Hideyosi attacked the Hojo’s territory with over 200,000 soldiers, sending troops to not only Odawara Castle but also branch castles. For example, Kanayama Castle where a magistrate from the Hojo governed was easily open by the troops. However, the only 500 defenders with 2500 residents in Oshi castle, instructed by Nagachika, never surrendered against over 20,000 attackers.

Castle is attacked by Inundation tactics in Battle of Oshi Castle

The Portrait of Hideyoshi Toyotomi, attributed to Mitsunobu Kano, owned by Kodaiji Temple (licensed under Public Domain via Wikimedia Commons)

The commander head of the attackers was Mitsunari Ishida, a highly trusted retainer from Hideyoshi, who was also supported by other lords, such as Nagamasa Asano and Masayuki Sanada. Hideyoshi was not there, but he ordered Mitsunari to flood the castle by making banks surrounding it to keep more water. His idea probably came from the geographical features and his successful experience of the Battle of Bicchu-Takamatsu Castle where he did the same way. It is said that Mitsunari put his strong hold on Maruhakayama-Kofun, an Ancient Burial Mound, about 2km away from the castle in the south. His team rapidly built 15 to 25 km banks around the mound in few days to dam water from the rivers. A folk story remains that farmers were asked to bring earth bags to build banks for a high fee.

The portrait of Mitsunari Ishida, owned by Hajime Sugiyama (licensed under Public Domain via Wikimedia Commons)

The partially remaining bank Mitsunari built, called Ishida Tsutsumi

It is uncertain if his attempt was successful according to some records in which the defenders secretly cut part of the banks to drain water drowning some attackers. The fact is that when the supporting lords tried to assault the castle, Hideyoshi ordered them to stop it and continue the inundation. The siege lasted for about a month, however, the castle couldn’t be beaten until the master Hojo surrendered in Odawara Castle. The castle has been nicknamed “a floating castle” of “a turtle castle” which probably originate from what the castle looked like in the siege.

“The illustration of the Narita Clan’s Oshi Castle during the Tensho Era”, it was made by a local historian to consider the Battle of Oshi Castle during the Meiji Era, exhibited by the Gyoda City Local Museum

The Horikiri-bashi Bridge where the bank was cut according to a local tradition

Castle becomes important defense site for Edo

In the Edo Period, Oshi Castle was governed by relatives or hereditary vassals of the shoguns as the Oshi Domain. This was because this castle was located in an important defensive site for Edo Castle, the shogun’s home base in the south. It is said that the Abe Clan, which often became members of shogun’s council of elders, completed the castle. They still used the basic structures of the castle as the island-like enclosures among the moats and marshes. However, they improved the castle’s defense systems more by building the three-level turret (similar to the Main Tower), other turrets and gates. The castle and domain were finally followed by the Okudaira-Matsudaira Clan, whose origin was the son of Nobumasa Okudaira who contributed to Ieyasu Tokugawa, the founder of the shogunate, in the Battle of Nagashino Castle and was married with Ieyasu’s daughter. They were trusted in and ordered by the shogunate to guard the No.3 Shinagawa Battery facing Edo Bay to prepare for possible threat to Western battleships at the end of the Edo Period.

The miniature model of Oshi Castle during the Edo Period, exhibited by the Gyoda City Local Museum

The rebuilt three-level turret of Oshi Castle, it was built in a different position from the original one

To be continued in “Oshi Castle Part2”

タグ: Maruhakayama ancient burial mound

118.Oshi Castle Part3