Battle of Bubaigawara

分倍河原の戦い

Ashikaga Clan

Musashi Province

Uesugi Clan

Date:  1/21 to 1/22 of Entoku 4 (1455)

Location:  Bubaigawara on the shores of the Tama River in Musashi Province

Outcome:  In a prelude to the Kyōtoku Conflict, the army of Ashikaga Shigeuji (the Koga kubō) launched a surprise attack against the Uesugi army led by Uesugi Noriaki, overcoming the numerical superiority of the Uesugi and scattering their forces.

Lord:  Ashikaga Shigeuji (Koga kubō)

Commanders:  Yūki Shigetomo

Forces:  500 mounted soldiers

Losses:  Unknown

Lord:  Uesugi Fusaaki

Commanders:  Uesugi Noriaki, Uesugi Akifusa, Nagao Kagenaka

Forces:  2,000 mounted soldiers

Losses:  Unknown

The Battle of Bubaigawara occurred from 1/21 to 1/22 of Entoku 4 (1455) toward the end of the Muromachi period.  In Bubaigawara along the shores of the Tama River in Musashi Province, this battle was waged between forces of the Kamakura kubō led by Ashikaga Shigeuji and forces of the kanrei, or deputy shōgun, of the Kantō led by Uesugi Akifusa (with Uesugi Fusaaki, a shugo daimyō, serving as the commander-in-chief from Kyōto).  This battle served as the opening act of the Entoku Conflict, the largest conflict in the Muromachi period comparable to the Ōnin-Bunmei War.

Occurring in the late Muromachi period, this Battle of Bubaigawara is separate from a conflict under the same name that occurred between the Kamakura bakufu army and Imperial forces loyal to Emperor Go-daigo in the spring of 1333 in the Kamakura period.

Background

Ten years after the decimation of the Kamakura kubō as a result of the Entoku Conflict, a movement arose to resuscitate the Kamakura administration.  Owing to a history of confrontation between the Muromachi bakufu and Kamakura kubō, officials of the bakufu in Kyōto were skeptical of these developments.  Hosokawa Katsumoto, the deputy shōgun, advocated against the plan, while Hatakeyama Mochikuni, the former deputy shōgun, favored it.  Based on the entreaties of Uesugi Fusasada, the military governor of Echigo, the administration finally consented.

Eijuōmaru, the orphan of Ashikaga Mochiuji (the prior kubō eliminated by the bakufu) was chosen as the next Kamakura kubō.  Meanwhile, Uesugi Noritada, the son of Uesugi Norizane (the prior deputy shōgun of the Kantō) of the Yamauchi-Uesugi family was chosen to serve as the deputy to Eijuōmaru.  Eijuōmaru pressed Noritada to refuse the appointment on the belief that Noritada resented Eijuōmaru and his sons owing to the Eikyō Conflict that was triggered by a clash of opinions between Norizane (who by this time had entered the priesthood) and Mochiuji.  However, Nagao Kagenaka (the kasai, or head of house affairs of the Yamauchi-Uesugi family) and Ōta Sukekiyo (the kasai, or head of house affairs of the Ōgigayatsu-Uesugi family) strongly recommended that Noritada accept the appointment so Noritada complied with their request.

In 1447, Eijuōmaru and Uesugi Noritada went to Kamakura whereupon Noritada was appointed as the deputy shōgun of the Kantō.  Two years later, in 1449, Eijuōmaru attended his coming-of-age ceremony and was invested with the title of Junior Fifth Rank (Lower) and Director of the Imperial Cavalry of the Left Division.  He also received one of the characters from the name of Ashikaga Yoshishige (later known as Yoshimasa), adopting the name of Ashikaga Shigeuji and formally assuming the role as the fifth Kamakura kubō.  Nevertheless, appointments by Shigeuji of Yūki Shigetomo, Yanada Mochisuke, Satomi Yoshizane (the orphans of bushō martyred for the Kamakura kubō in the Eikyō Conflict and the Battle of Yūki which was waged between the Muromachi bakufu and wealthy families from the Kantō led by the Yūki) triggered opposition by the Uesugi clan and their band of retainers.

In 1450, an incident occurred whereby, acting upon orders of Shigeuji, Yanada Mochisuke seized control of the Nagao neighborhood in the Kamakura District of Sagami Province.  This land was the birthplace of the Nagao clan who served as the leaders among the senior retainers of the Uesugi family.  This was the location of the Goryō Shrine – the principal site for memorial services of the ancestors of the Nagao clan.  The members of the Nagao clan led by Nagao Kagenaka severely resented this action, and, together with Ōta Sukekiyo (the son-in-law of Kagenaka) vociferously opposed it, but Shigeuji did not consent to returning the neighborhood.

On 4/20 of Hōtoku 2 (1450), Nagao Kagenaka and Ōta Sukekiyo brought 500 mounted soldiers to Kamakura and launched a coup d’état.  After receiving prior notice of the plan, Shigeuji, with the protection of Oyama Mochimasa and others, escaped from Kamakura under cover of darkness  and took refuge on the tied island of Enoshima.  On 4/21, after entering Kamakura, Kagenaka approached Enoshima in pursuit of Shigeuji.  At this time, Oda Mochiie, Utsunomiya Hitotsuna, and Chiba Tanemasa deployed in support of Shigeuji and clashed against the forces led by Kagenaka at Yuigahama on the shores of the Sagami Bay in an event known as the Battle of Enoshima.

In addition to an ignominious defeat suffered by the combined forces of the Nagao and Ōta, it became known that, without knowledge of the situation, their lord, Uesugi Noritada, sent members of the Obata clan to rescue Shigeuji so Kagenaka and Sukekiyo fled to the Kasuya residence of Uesugi Mochitomo, their lord and the former head of the Ōgigayatsu-Uesugi family.  Although Noritada was not at all involved in the incident, after it was understood that Nagao and Ōta forces launched the attack, he was confined to his residence.

After being informed of the event, the bakufu assigned Hatakeyama Mochikuni (who had been restored as the deputy shōgun) to arbitrate, and a verdict favorable to Shigeuji was rendered.  On this basis, on 8/4, Shigeuji returned to Kamakura and, in the tenth month, Noritada returned to his position and, upon entreaties made on their behalf, Nagao Kagenaka and the others were pardoned.  Thereafter, however, incidents by which bushi aligned with Shigeuji and Noritada seized the landholdings of opposing camps frequently occurred.

Hosokawa Katsumoto, after having replaced Mochikuni again as the deputy shōgun, changed direction and endeavored to reduce the authority of the Kamakura kubō.  Katsumoto considered that if Uesugi Mochitomo (the father-in-law of Noritada) is left unchecked, Mochitomo would pose a risk to the safety of Noritada who was also Katsumoto’s son-in-law.  Therefore, he secretly joined with Nagao Kagenaka to enter Kōzuke Province (the home province of the Uesugi clan) and engaged in preparations to eliminate Shigeuji.

Meanwhile, based on a grasp of these developments, Ashikaga Shigeuji and those around him began to secretly formulate plans to respond.

Course of events

On the night of 12/27 of Kyōtoku 3 (1455), Uesugi Noritada, who was in the residence of the deputy shōgun in Kamakura, received urgent orders to visit him from Ashikaga Shigeuji.  At that moment, owing to the approach of the new year, Nagao Kagenaka was visiting the Goryō Shrine in the Nagao neighborhood and entrusted his older brother-in-law, Nagao Sanekage, who was the kasai, or head of house affairs, to keep watch while Kagenaka was away.  Noritada then went to Shigeuji’s residence.

Upon entering the residence, however, Noritada was surrounded by a unit of soldiers led by Yūki Shigetomo, Satomi Yoshizane, and Takeda Nobunaga.  Noritada, having no options, was then summarily killed by retainers of the Yūki, Tagaya Takatsune and Tagaya Ujiie (brothers).  Around this time, a detached unit led by Iwamatsu Mochikuni launched an attack against the residence of the deputy shōgun and Sanekage and others killed the retainers of the Uesugi family.

After hearing of the assassination of Noritada, Kagenaka returned to Kamakura and promptly set fire to the residence of the deputy shōgun.  He then evacuated Noritada’s formal wife (the daughter of Uesugi Mochitomo) and other surviving family members to the Kasuya residence of Mochitomo.  Upon arriving at the residence, Kagenaka held a meeting with key members of the Uesugi family including Mochitomo, Mochitomo’s eldest son, Uesugi Akifusa (the head of the Ōgigayatsu-Uesugi family), Uesugi Noriaki (of the Inugake-Uesugi family), and Uesugi Fujitomo (of the Oyamada-Useugi family) during which they agreed to back Noritada’s younger brother, Uesugi Fusaaki who was in Kyōto to serve as the next deputy shōgun of the Kantō and to eliminate Shigeuji.  Furthermore, Kagenaka went straight away to their territory in Kōzuke to gather troops and sent a messenger to Uesugi Fusasada, the military governor of Echigo Province, to request reinforcements.  He then sent his eldest son, Nagao Kagenobu, directly to Kyōto to notify the bakufu of the situation and to meet with Fusaaki.

On 1/5 of Kōshō 2 (1456), to attack the home province of the Uesugi in Kōzuke, Shigeuji departed from Kamakura and entered the Kōan Temple in Fuchū in Musashi Province.  Upon hearing this news, Uesugi Mochitomo deployed with the aim of capturing Kamakura while Shigeuji was absent.  On the next day, however, at Shimagawara in Sagami Province, he was intercepted and defeated by forces led by Takeda Nobunaga who was protecting Kamakura while Shigeuji was away.  Nagao Kagenaka then led his forces from Kōzuke and Musashi to attack Fuchū while members of the Uesugi deployed in an effort to converge with his army.

On 1/21, after amassing in the environs of Fuchū, the Uesugi army with 2,000 mounted soldiers attacked the Kōan Temple, but Shigeuji’s army charged out to Bubaigawara with 500 mounted soldiers.  Caught by the surprise attack by Shigeuji’s men, the Uesugi forces fell into disarray.  In the vanguard, Uesugi Noriaki clashed with the enemy at nearby Tachikawahara.  After incurring a near-fatal injury, he was narrowly rescued by retainers, only to kill himself at the Takahata-Fudōson Kongō Temple.  After learning that Noriaki had killed himself, Norifusa became upset and, on the next day, led 500 mounted soldiers to attack Shigeuji’s army at Bubaigawara.

At the outset of hostilities, Ōishi Fusashige, a member of the Uesugi vanguard unit, was killed, but Shigeuji’s army also incurred numerous losses so the battle ebbed and flowed without significant progress on either side.  At this point, in the midst of an assault by forces under Yūki Shigetomo, the Uesugi army began to retreat, but their route back to Sagami had been severed, causing them to scatter in an easterly direction.  Nevertheless, Shigeuji’s army led by Shigetomo continued the pursuit, surrounding the Uesugi at Yase in Musashi.  On 1/24, Akifusa and Fujitomo took their own lives, while, having escaped danger, Nagao Kagenaka collected the remaining forces and barely escaped to Oguri Castle in Hitachi Province.

Consequences

Riding the momentum, Shigeuji launched a series of attacks against bases of the Uesugi in Musashi Province.  After learning that Nagao Kagenaka was in Oguri Castle, on 3/3, he entered Koga Castle in Shimōsa Province, and, after gathering additional troops including Nasu Sukemochi, Tsukuba Urutomo, and Oda Tomohisa, commenced an attack against Kagenaka at Oguri Castle.  While en route, notwithstanding the sudden death of Tomohisa, in the fourth month, the forces toppled the castle and sent Kagenaka fleeing in defeat.  Meanwhile, in the Ōgigayatsu-Uesugi, Akifusa’s son, Uesugi Masazane, became the next head of the family, while Ōta Sukenaga (later known as Ōta Dōkan) became the kasai, or head of house affairs, in place of his father, Ōta Sukekiyo, who took responsibility for the death in battle of Akifusa and entered the priesthood.

Soon after the start of the new year, news of this battle reached the Muromachi bakufu in Kyōto.  Partial support for Shigeuji led to contentious debate.  Finally, in the third month, upon the wishes of Hosokawa Katsumoto (the deputy shōgun of the bakufu), an order to eliminate Shigeuji was given to the members of the Uesugi family, in addition to military governors in the region including Imagawa Noritada of Suruga Province, Ogasawara Mitsuyasu of Shinano, Utsunomiya Tomotsuna of Shimotsuke, and Chiba Tanenao (the prior military governor of Shimōsa).  At the Battle of Enoshima, the Utsunomiya and Chiba clans supported Shigeuji, but, a predecessor, Utsunomiya Mochitsuna (the thirteenth head of the family) had been killed by Shigeuji’s father, Ashikaga Mochiuji, so the clan was seeking to avenge the loss.  With respect to the Chiba clan, Chiba Tanemasa (the military governor of Shimōsa and Kazusa provinces), who was the head of the family at the time of Enoshima, died suddenly while his father, Chiba Tanenao, who was opposed to Mochiuji, reasserted his authority.  For these reasons, the Utsunomiya and the Chiba joined the Imagawa and Ogasawara clans to form an army to eliminate Shigeuji.

After receiving a war banner from Emperor Go-hanazono, Imagawa Noritada, who was in Kyōto at the time, immediately returned to Suruga Province to deploy troops.  On 6/16, he defeated Takeda Nobunaga and occupied Kamakura.  Uesugi Fusasada, the military governor of Echigo, secretly returned from Kyōto to Echigo to back Uesugi Fusaaki as the next deputy shōgun of the Kantō.  Next, at Sannomiya in Kōzuke, Iwamatsu Mochikuni led forces in a clash against supporters of Shigeuji from Kōzuke.  After a direct attack by Shigeuji, Utsunomiya Tomotsuna lost Utsunomiya Castle and, as a result, was ousted by his senior retainers.  Meanwhile, Chiba Tanenao was decimated in an attack by Hara Tanefusa, a senior retainer backing Makuwari Yasutane in a faction opposed to the army formed to subjugate Shigeuji.

Having assessed the situation, Shigeuji determined it would be difficult to return to Kamakura, so he went to Koga Castle and declared it would be his temporary residence.  This is known as the Koga kubō.  Thereafter, although conflicts between Shigeuji’s forces and the Uesugi army persisted across the Kantō, gradually, Shigeuji garnered control to the east of the Tone River while the Uesugi forces took over the west side.  In particular, in the seventh month of 1455, owing to reasons of warfare, the Imperial Court changed the name of the era from Kyōtoku (1452 to 1455) to Kōshō (1455 to 1457).  While, to the west of the Tone River, the Uesugi adopted the new era name, Shigeuji’s camp to the east of the Tone River continued to use Kyōtoku, refusing to adopt the new era name in response to the undeserved efforts by the bakufu and Imperial Court to track down and kill the members of Shigeuji’s camp.  Thereafter, despite five more changes to era names, Shigeuji’s camp continued for twenty-three years to refer to the Kyōtoku era as a sign of opposition and, during the Ōnin-Bunmei War in the capital of Kyōto, continued to have an antagonistic relationship with the bakufu and the Imperial Court.

Later, this turned into the Kyōtoku Conflict embroiling the Kantō Region in chaos for a period of twenty-eight years.