Japan Castle Explorer: Nagakubo Castle -Bridgehead of Takeda clan to east part of Shinano province-

Nagakubo Castle

-Bridgehead of Takeda clan to east part of Shinano province-

Name: Nagakubo castle (Nagakubo-jo)
Alias: Fukayama-jo (Fukayama-castle), Kasumino-o jo (Kasumino-o castle)
Place: Furumachi Nagawa-town, Nagano
Type: Mountain Castle
Built: 15th century?
Remaining remnants: Clay walls and dry moats
Title:

Brief History

Nagakubo castle (長窪城) is located over a peninsular like ridge of 90 meter height from hillside at riverbank of Yoda-gawa river. in the center of Nagakubo area of Nagawa town. Nagakubo area is a bow like shaped valley of about 3 kilometer long and 500 meter width, at 6 kilometer south from current Ueda city central.

Nagakubo area is a small valley at the north of Chikuma mountains, but it is an importance place of communication where Nakasendo-road that is a mountain artery between Edo city and Kyoto city of Edo era from Suwa area toward Saku area, and Daimon-Kaido road from Ueda area to Chino area meets like X letter. The south edge of Nagakubo area was a posting town of Nakasendo-Road.

Origin of Nagakubo castle

The origin of Nagakubo castle is not clear but it might be built by local lord Oi clan. Oi clan was a branch family of Ogasawara clan, a traditional family of Minamoto clan and later was appointed as the governor of Shinano province (Nagano prefecture). Oi clan diverged from Ogasawara clan in the beginning of Kamakura era, and at first resided at Iwamurada area of current Saku city.

Oi clan prospered in the former half of Muromachi era and managed most part of Saku providence and was appointed as the deputy governor of Shinano province by its main family Ogasawara clan. But in 1400 Ogasawara clan tried to manage the province directly was broken by the alliance of major local lords such as Murakami clan, and Oi clan also faced the antipathy of local lords.

In the former half of 15th century, Oi clan became opponent with Ashida clan, a local lord of Ashida castle (Nagano prefecture) resided at Ashida area at 10 kilometer west of Saku area. Oi clan attacked Ashida clan and their supporters and broke them, then Ashida clan surrendered to Oi clan and became its retainer.

Fall of main family of Oi clan

Nagakubo castle is located at the entrance of mountain road to Ashida area that is current Route 254, and there already might be a fort built by Ashida clan. Oi clan utilized this fort and might expand it as a base in Nagakubo area, for the purpose of local administration and contact with Ogasawara clan which resides at Matsumoto basin ahead of Tobira-Toge pass from Nagakubo area.

In the latter half of 15th century, large powers surrounding Saku region such as Takeda clan which was the governor of Kai province (Yamanashi prefecture), Murakami clan which was the lord of Kazurao castle (Nagano prefecture) or Yamanouchi Uesugi clan which was Kanto Kanrei and the lord of Kozuke province (Gunma prefecture), grew into warlords.

In 1472 Oi clan intruded into Kai province and fought with Nobumasa Takeda (1447-1505), a grand-grandfather of Shingen Takeda (1521-1573), but failed the attempt and reversely attacked by Takeda army. Furthermore declined Oi clan was attacked by Murakami clan in1483, then Oi castle fell and main family of Oi clan was ruined, But branch family at Nagakubo castle remained as Nagakubo clan.

Invasion of external powers

After that for decades Takeda clan fell into their internal conflict and peaceful year continued. But Nobutora Takeda (1494-1574), the father of Shingen Takeda and ended internal conflict of Kai province started external expansion since 1520’s. Nobutora at first attacked Saku region in 1528 next fought with Yorimitsu Suwa (1473-1540), the leader of Suwa clan which was the lord of Suwa region and priest of Suwa Shrine, but failed it.

Nobutora Takeda and Yorimitsu Suwa allied in 1535, and marched to Saku region along with Yoshikiyo Murakami (1501-1573), the leader of Murakami clan. In 1541, ally of three clans broke Unno clan and its family at the battle of Unno-daira, and expelled Unno family from Saku region. At this battle Nagakubo castle was fallen by Yorishige Suwa (1516-1542), and Sadataka Oi (?-?), the commander of Oi clan once escaped.

But at this year, Nobutora Takeda was expelled by his son Shingen Takeda due to famine and too much military operation. Shingen Takeda broke the treaty with Suwa clan, then in 1542 Shingen attacked Suwa clan and broke it. Yorishige Suwa was forced to suicide then Suwa clan was ruined as an independent warlord. During this confusion Sadataka Oi once recovered Nagakubo castle.

But Shingen Takeda who ruined Suwa clan and built his bridgehead at Shinano province accelerated his invasion. Next year in 1543 Shingen attacked Nagakubo castle and captured Sadataka Oi. As Nagakubo castle is located at an entrance from Suwa area to Saku area, Shingen reformed Nagakubo castle and used is as a bridgehead to Saku providence.

Structure of Nagakubo castle

Central area of the castle is a table shaped one of about 40 meter long and 30 meter wide, which is divided into upper half at front side and lower half at rear side. At the backward of upper half there is a basement of watchtower, and there is a ruin of clay wall. According to the information there is a ruin of small stone wall.

At the south of central area where is the front side of the castle, there is a layer of terraces built at slope, which is separated by dry moats. At the halfway there is a relatively large flat space of about 30 meter long, which is said as stable. Main entrance of the castle was a narrow space between the mountain and creak at hillside.

North of central area where is the back side of the castle is a weak point of the castle directly connected to backside mountain. To secure this direction, the slope is separated by combination of five large dry moats which prolong to the halfway of the slope. Ahead of dry moats a narrow terrace spreads toward the saddle point, which might be used as a riding space.

Bridgehead of Shingen Takeda to Saku region

Around this time Shingen simultaneously proceeded attack to various enemies of Shinano province. In 1545, Shingen attacked Takato clan which was the lord of Takato castle (Nagano prefecture) and once allied to ruin Suwa clan, then captured Takato castle. Next Shingen turned his army to Uchiyama castle (Nagano prefecture) at Saku region, which was protected by Sadakiyo Oi (?-1575), the younger brother of Sadataka Oi.

Sadakiyo Oi once resisted but surrendered, and Takeda clan also used Uchiyama castle as another bridgehead. Further in 1547, Takeda army attacked Shiga castle which was the castle of Kasahara clan and still resisted against Shingen, and after fierce attack Shingen fell Shiga castle then captured whole part of Saku region.

Now Shingen had to face with Yoshikiyo Murakami, who was the major local lord of middle part of the province and formerly held Saku region. In 1548, Shingen visited Nagakubo castle then marched to Kazurao castle, then faced Murakami army at Uedahara.

Revival after defeat

However, at the battle of Uedahara Shingen suffered severe defeat and lost important generals such as Nobukata Itagaki (1489-1548) and Torayasu Amari (1498?-1548). Shingen retreated to Kai province, and Ogasawara clan which held Matsumoto area and already had a tension with Takeda clan raised their army against Takeda clan.

But anti Takeda powers could not move cooperatively, thus Shingen Takeda separately attacked them. Just after the battle of Uedahara, Shingen assaulted Ogasawara army at the battle of Shiojiri Toge, then limited the movement of Ogasawara army. Then Shingen marched to Saku region and captured several castles left Shingen after the battle of Uedahara.

Next year in 1550, Shingen attacked Ogasawara clan again and fell Hayashi castle (Nagano prefecture), the main base of Ogasawara clan. Nagatoki Ogasawara (1514-1583) left the castle and fell into exile, and Shingen Takeda captured Matsumoto basin. Removing Ogasawara clan, Shingen planned next attack of Murakami clan and visited Nagakubo castle again.

Second fail and unexpected end

In august of 1550, Shingen encircled Toishi castle (Nagano prefecture), an important branch castle of Murakami clan at Ueda basin. But Toishi castle was a secure castle and Shingen could not fall it for one month, and Yoshikiyo Murakami who fought with Takanashi clan quickly agreed and returned.

Shingen judged the situation unfavorable and retreated, but due to the chase of Murakami army Shingen suffered damage again. Yoshikiyo Murakami restored his authority and started to attack the castle of Takeda clan along with Nagatoki Ogasawara again. Unite of Shinano province seemed remote to Shingen Takeda at this point.

However in 1551, Toishi castle suddenly fell by the plot of Yukitsuna Sanada (1513-1574, famous as Yukitaka Sanada). Yukitsuna was once broken at the battle of Unno-daira and exiled to Yamanouchi Uesugi clan, but returned to Shinano province and became the retainer of Shingen. Yukitsuna might visit Nagakubo castle and planned his plot against Yoshikiyo Murakami with Shingen.

Afterward of castle

After the fall of Toishi castle, Shingen fell remaining branch castles of Murakami clan and also turned the retainer of Yoshikiyo Murakami to his side. Finally in 1583, Shingen fell Kazurao castle, the main base of Murakami clan without resistance. Yoshikiyo Murakami exiled to Kenshin Uesugi (1530-1578), the warlord of Echigo province (Niigata prefecture), and Shingen expanded his territory just before of Nagano basin.

However, Kenshin Uesugi who protected Yoshikiyo Murakami intruded into former territory of Murakami clan and once recovered Kazurao castle. In response to this, in 1553 Shingen visited Nagakubo castle again, and attacked Shiota castle (Nagano prefecture) where Yoshikiyo besieged. Shingen fell Shiota castle and Yoshikiyo Murakami escaped again.

After this battle, as front line moved northward into Nagano basin, Shingen became to use Fukashi castle (Nagano prefecture, later Matsumoto castle) as a strategic base and Nagakubo castle was ceased to use. Old type structure of Nagakubo castle shows this movement, and Nagakubo castle might be abolished after the fall of Takeda clan in 1582.

Today no building remain but structure of the castle well remain on the mountain. The castle seems too small for corps of Takeda army but this was a minimum lodge of the lord and soldiers might stay hillside. Frequent visit of Shingen to this castle shows both of hard fights and steady progress of invasion of Shingen toward Murakami clan.

Access

30 minutes drive from Joshinetsu Jidoshado Expressway Tobu Yunomaru interchange. Forest road starts Route 254 to backside of castle with parking space.