Revolt of Nagao Kageharu
The Revolt of Nagao Kageharu occurred from Bunmei 8 (1476) to Bunmei 12 (1480). This was a revolt by Nagao Kageharu, a powerful retainer of the Uesugi clan who served as the deputy shōgun of Kantō. The revolt was suppressed through the efforts of Ōta Dōkan, the kasai, or head of house affairs, of the Ōgigayatsu-Uesugi family.
In the Eikyō Conflict of 1439, Ashikaga Mochiuji (the Kamakura kubō) was eliminated by Uesugi Norizane upon orders of Ashikaga Yoshinori, the sixth shōgun of the Muromachi bakufu who was later assassinated in an event known as the Kakitsu Disturbance. Mochiuji’s orphan, Ashikaga Shigeuji, succeeded him and led a new Kamakura kubō. Shigeuji, however, harbored resentment toward the Uesugi clan who served as the deputy shōgun of the Kantō and were responsible for the killing of his father. In 1454, he assassinated Uesugi Noritada (the deputy shōgun of the Kantō), triggering a full-scale war against the Uesugi. Under attack by the bakufu army operating in concert with the Uesugi, Shigeuji fled Kamakura to Koga Castle in Shimōsa Province and assumed the title of Koga kubō and plunged into conflict with Ashikaga Masatomo (the Horigoe kubō) dispatched by the bakufu and both branches of the Uesugi family (the Yamanouchi-Uesugi and the Ōgigayatsu-Uesugi). This is known as the Kyōtoku Conflict.
The Yamanouchi-Uesugi and the Ōgigayatsu-Uesugi originated from the same Uesugi clan, but the Yamanouchi-Uesugi inherited the role of deputy shōgun of the Kantō while the Ōgigayatsu were a cadet family possessing less than one-half of the territory as the Yamanouchi branch in which Nagao Kagenobu served as the kasai, or head of house affairs. In battles against the Koga kubō, the Ōgigayatsu supported the Yamanouchi. In particular, the contributions of the head of house affairs, Ōta Sukekiyo (Dōshin), and his son, Ōta Sukenaga (Dōkan) were significant. Sukekiyo and Sukenaga rebuilt Iwatsuki Castle and built Kawagoe and Edo castles to protect the Kantō as well as serve as bases for attack against their enemies.
The Kyōtoku Conflict continued for over twenty years without a clear victor. The main force of the two branches of the Uesugi established a base in Ikakko in the Kodama District of northern Musashi Province to oppose the Koga kubō for eighteen years, known as the Ikakko Campaign.
In 1473, Nagao Kagenobu died at Ikakko. Kagenobu came from the Shiroi-Nagao family and served as the head of house affairs for the Yamanouchi branch. Kagenobu’s son, Nagao Kageharu, succeeded his father as the head of the Shiroi-Nagao family. Earlier in the Muromachi period, the Nagao family had split between the Shiroi-Nagao branch (based at Shiroi Castle) and the Sōja-Nagao branch (based at Oumi Castle) in Kōzuke Province. After the demise of Kagenobu, Uesugi Akisada (the head of the Yamanouchi-Uesugi) assigned his former position as head of house affairs to Kageharu’s uncle, Nagao Tadakage, who was the fifth head of the Sōja-Nagao family. Although this role was filled by a retainer of a retainer, as an assistant to the deputy shōgun of the Kantō, the role carried significant authority.
The Nagao family was divided between the Shiroi-Nagao, the Sōja-Nagao, the Inugake-Nagao, and the Kamakura-Nagao (later known as the Ashikaga-Nagao family). The role of kasai, or head of house affairs, was performed on a rotating basis by these families. Originally, however, these individuals came from the Kamakura-Nagao branch who were the lineal descendants of the Nagao family and, secondly, from the Inugake-Nagao. If, in the case of these two branches, there were no suitable candidates owing to the absence of a head of the family or a head who was too young, then a candidate would be chosen from among the elders of the Shiroi and Sōja branches. Nevertheless, upon the murder of Uesugi Noritada, as a consequence of the killing of Nagao Sanekage (the head of the Kamakura branch) and Nagao Norikage (who had become the successor to the Inugake branch), Nagao Kagenaka (Kageharu’s grandfather) followed by Nagao Kagenobu from the Shiroi branch served in the position as head of house affairs for two successive generations. Kagenobu was the second son of Kagenaka so Nagao Tadakage (the younger brother of Kagenobu) could not become a rival.
Based on the above reasoning, the most powerful individual to serve as the next head of house affairs was Nagao Kagehito of the Ashikaga-Nagao branch (the Kamakura-Nagao moved to the Ashikaga manor), but he died early in the year prior to the death of Kagenobu, while his son and heir, Nagao Sadakage, as well as the head of the Inugake-Nagao, Nagao Fusakiyo (the younger brother of Kagehito), were too young to serve as the head of house affairs. Nagao Tadakage was a veteran who had served in critical roles for the family including as the deputy military governor of Musashi. Following the demise of his adoptive father (Nagao Tadamasa, who served as the head of house affairs prior to Kagenaka), the selection of Tadakage as the successor to Kagenobu was not unnatural given the prior methodology for filling the position of head of house affairs. Meanwhile, after having members of the Shiroi-Nagao serve in the role for two successive generations, Uesugi Akisada feared the branch would become too strong, providing another reason to assign the role to Tadakage instead of Kageharu.
Despite the reasons for the decision, Kageharu became deeply resentful toward those involved. Moreover, during the period that the Shiroi-Nagao held the role of head of house affairs, bushi under the command of the Yamanouchi-Uesugi had established relationships with the family by which to receive income and recognition of their rights to their landholdings. By having the role move from the Shiroi-Nagao to the Sōja-Nagao, these bushi feared the loss of their rights and desired Kageharu to succeed to the position to preserve their security. In particular, along with transition of the role, issues arose in regard to inherited landholdings leading to clashes between bushi affiliated with one of the families against those affiliated with the other.
Kageharu sought like-minded support from his cousin, Ōta Dōkan, but Dōkan refused him and promptly went to inform Akisada and his lord, Uesugi Sadamasa (the head of the Ōgigayatsu-Uesugi) at their base at Ikakko. In a bid to placate Kageharu, Dōkan recommended to Akisada and Sadamasa to assign to Kageharu the role of deputy military governor of Musashi, but Tadakage detested the prospect of having Kageharu in a position just after him and held both positions in an atypical situation. In that case, Dōkan recommended the temporary removal of Tadakage but Akisada disagreed, whereupon he then advised an immediate deployment to subdue Kageharu, but, owing to their opposition to Ashikaga Shigeuji (the Koga kubō), this could not be done either. More than anything else, with the founder of the Ashikaga-Nagao branch (Nagao Kagehito) having died in 1472, it was natural for Tadakage as a veteran in the Nagao family to assume the role as the head of house affairs, while the assertions of Kageharu were viewed as undeserved. Meanwhile, after admonishing Akisada to temporarily remove Tadakage from the position, Dōkan received push-back not only from Akisada and Tadakage but also from other senior retainers of the Uesugi, in addition to criticism from his father, Sukekiyo.
In the sixth month of 1476, Kageharu raised arms from his base at Hachigata Castle in Musashi while Dōkan was staying in Suruga to intervene in an internal dispute in the Imagawa clan. Akisada and Tadakage dismissed the strength of Kageharu, but Kageharu was a superior warrior. Moreover, after members of the Shiroi-Nagao served as the head of house affairs of the Uesugi for two generations, the family acquired more power than other branches of the Nagao clan. Bushō serving at the main base of the Uesugi at Ikakko were shaken by the rebellion and some returned on their own accord to their home provinces.
In the first month of 1477, Kageharu led a cavalry of 2,500 soldiers on a surprise attack against the main base at Ikakko. Akisada and Sadamasa incurred a major defeat and fled to Kōzuke. The most important base of the Uesugi from which to oppose the Koga kubō over a period of eighteen years fell to Kageharu and a relatively small cavalry battalion.
Course of events
Those acting in concert with the rebellion launched by Nagao Kageharu included Echigo Goroshirō of Koiso Castle in Sagami, Kaneko Kamon-no-suke of Ozawa Castle in Sagami, Mizorogi Masashige of Mizorogi Castle (a servant of Kageharu), and Yano Hyōgo of Kozukue Castle. In addition, many kokujin, or provincial landowners, and jizamurai, or local samurai, allied with Kageharu, amounting to a formidable force. The Toshima clan, a renowned family of southern Musashi, was supportive of the rebellion. The Toshima clan were powerful retainers of the Kamakura bakufu, but, in the Muromachi period, their former territory was taken over by the Ōta clan. The head of the family, Toshima Yasutsune, was based in Shakujii and Nerima castles, while his younger brother, Toshima Yasuaki, was based in Hiratsuka Castle. Communications routes between Edo Castle on one hand and Kawagoe and Iwase castles on the other hand were severed.
In the third month of 1477, Dōkan burst out with the vanguard forces, toppling Mizorogi and Koiso castles with rapid assaults, and then attacked Ozawa Castle, but the garrison put-up a stiff defense and Kageharu sent reinforcements so Dōkan had to pull-back his forces. Yano Hyōgo of Kozukue Castle deployed with the aim of attacking Kawagoe Castle, but he was repelled by Ōta Suketada (Dōkan’s nephew) and Ueda Kōzunosuke.
Dōkan had to quickly crush the Toshima clan who were expanding their power beckoning Edo Castle. In the fourth month of the same year, after receiving reinforcements including Uesugi Tomomasa and Miura Takahira, Dōkan sent lightly armed forces to burn down the area below Hiratsuka Castle. Viewing the small force with disdain, Yasutsune and Yasuaki came out of the castle and, by setting an ambush, a force of 50 mounted soldiers defeated a force of 200 mounted soldiers from the Toshima army, killing Yasuaki in an event known as the Battle of Egota-Numabukuro. Dōkan chased after Yasutsune and surrounded Shakujii Castle. Yasutsune proposed a surrender, but the condition to demolish the castle was not carried out so Dōkan attacked and toppled the castle while Yasutsune escaped under cover of darkness.
In the fourth month of the same year, Kageharu deployed to Ikkako, traversed the Tone River, and attacked the armies of Akisada and Sadamasa on the Hachiya Plains but was repelled. In the fifth month, Dōkan converged with Akisada and Sadamasa and recovered Ikkako. At the Battle of Yōdohara, their combined forces crushed Kageharu’s troops. The combined forces then surrounded Hachigata Castle, but Ashikaga Shigeuji deployed with a cavalry of 8,000 soldiers so the forces laying siege to Hachigata were forced to retreat.
Dōkan attacked the base of Kageharu in Kōzuke. The opponents engaged in a standoff on the Shiouri Plains for one month and then, in the eleventh month, both sides withdrew. In the first month of 1478, Ashikaga Shigeuji, via Yanada Mochisuke, sounded out Nagao Tadakage (the head of house affairs for the Yamauchi-Uesugi family) in regard to a settlement. Through Dōkan’s efforts, Kageharu’s rebellion was short-lived, while, after more than twenty years of fighting, Shigeuji had grown weary of the war and sought a resolution based on conditions favorable to the Muromachi bakufu.
To impede the progress of settlement negotiations, in the first month of 1478, Toshima Yasutane raised arms again from Hiratsuka Castle, but Dōkan quickly suppressed it, causing Yasutane to flee to Kozukue Castle. In the third month, Kageharu attacked Kawagoe Castle, but was repelled by Sadamasa and Ōta Sukekiyo.
Seeking to subjugate those in Sagami (the base of the Ōgigayatsu-Uesugi) who supported Kageharu, in the third month, Dōkan attacked and toppled Ozawa Castle after having failed in the prior year. In the fourth month, he attacked Kozukue Castle. Yasutsune, who had been hiding out in the castle, could not be located and the well-known Toshima clan came to an end. Next, Dōkan destroyed outlying castles in Sagami that were aligned with Kageharu. In the seventh month, Dōkan attacked Kageharu’s base at Hachigata Castle and made it the base of Akisada.
Having secured Musashi and Sagami, in the twelfth month of 1478, Dōkan defeated Chiba Noritane, a powerful bushō opposed to the settlement, at the Battle of Sakainehara. In 1479, Dōkan dispatched his nephew, Ōta Suketada and Chiba Yoritane (from a branch of the Chiba aligned with the Uesugi) to the Bōsō Peninsula and had them attack Chiba Noritane who was holed-up at Usui Castle. Although Suketada was killed in this battle, the Mariyatsu-Takeda and Unakami clans surrendered and the attacking forces achieved a clean-sweep of opposition on the peninsula.
In the midst of peace negotiations with Shigeuji, Kageharu continued resistance from the Chichibu and Kodama districts of northern Musashi. In the sixth month of 1480, his last base at Hino Castle was attacked and captured by Dōkan. Kageharu relied upon Shigeuji to escape. Thereafter, Kageharu succeeded in breaking from Uesugi Norifusa (the adopted son of Akisada), received backing from the head of the Yamanouchi-Uesugi, assumed the role of head of house affairs, and aimed for a revival.
On 11/27 of Bunmei 14 (1482), Shigeuji and both branches of the Uesugi family reached a settlement known as the tohi gattai, an alliance between the central authorities in the capital of Kyōto and the Koga kubō in the Kantō. By this means, Shigeuji was pardoned by the bakufu. Moreover, Norisada returned to service under Akisada while Kageharu prepared for a revival under Shigeuji.
The alliance between the bakufu and the Koga kubō, along with the fall of Kageharu, brought to an end conflict in the Kantō that had persisted for thirty years. However, this settlement was driven by the Yamanouchi-Uesugi family and the Echigo-Uesugi family whereas Uesugi Sadamasa, the head of the Ōgigayatsu-Uesugi branch, was dissatisfied. Moreover, Ōta Dōkan expressed his dissatisfaction in a letter on the basis that the rewards given to him and his fighters were insufficient. Owing to this battle, Dōkan’s authority and popularity rose significantly, but this posed a threat to his lords, Akisada and Sadamasa.
in the seventh month of 1486, Dōkan was murdered by his lord, Uesugi Sadamasa, at the Kasuya residence. At the time of his death, he purportedly said the clan would be destroyed.
In 1487, the Uesugi family split between the Yamanouchi and Ōgigayatsu clans, plunging into a struggle between the clans known as the Chōkyō War. The fallen Nagao Kageharu allied with the Ōgigayatsu-Uesugi and resumed fighting against the Yamauchi branch. In 1493, at the height of this conflict, Ise Sōzui (later known as Hōjō Sōun) charged into Izu Province, decimated the Horigoe kubō, and advanced into Sagami Province. Before long, the Yamanouchi-Uesugi and the Ōgigayatsu-Uesugi would be vanquished by the Gohōjō clan funded by Ise Sōzui.