Nagao Kageharu's Rebellion

Overview

Nagao Kageharu's Rebellion was a revolt begun in Bunmei 8 (1476) by Nagao Kageharu, a senior retainer of the Yamanouchi Uesugi. On the 18th day of the 1st month of Bunmei 9 (1477), Kageharu launched a sudden attack on the Igako camp, which the Uesugi side had built to face the Koga kubō Ashikaga Shigeuji, and took it. While many powers in the Kantō answered Kageharu's call, Ōta Dōkan of Edo Castle fought from front to front, destroyed the Toshima and others, and on the 24th day of the 6th month of Bunmei 12 (1480) took the Hino fortress, suppressing the rebellion that Kageharu had based in Musashi.

The rebellion was an internal revolt of the Uesugi side in the midst of the Kyōtoku War. What stands out is that a dispute among the retainers of the Yamanouchi Uesugi, the house that supplied the Kantō Deputy Shogun, shook the very structure of the war against the Koga kubō.

Background and Kageharu's rising

In the Yamanouchi Uesugi house, the chief retainer (kasai) Nagao Kagenobu died in the 6th month of Bunmei 5 (1473). The kasai was the senior retainer who supported the master house. Kagenobu's son Kageharu hoped to succeed his father, but the post went to Kageharu's uncle Nagao Tadakage of the Sōja Nagao. Kageharu bitterly resented this.

Tadakage's appointment was carried out in the 12th month of Bunmei 6. Ōta Dōkan of Edo Castle sought a reconciliation between Kageharu and Tadakage but did not succeed. In Bunmei 7, Kageharu is said to have hinted at killing Uesugi Akisada and Uesugi Sadamasa of the Echigo Uesugi, heir of Uesugi Fusasada. Dōkan went to the Igako camp and told the Uesugi side of Kageharu's intent to rebel, but was not heard. Having failed to reconcile the two, he returned to Edo Castle.

In the 6th month of Bunmei 8, while Dōkan was in Suruga intervening in an Imagawa family dispute, Kageharu left the Igako camp and built Hachigata Castle in Musashi, where he took up residence. The Uesugi side regarded him as having fallen from favor and forcibly seized the lands attached to the chief-retainer post.

On the 18th day of the 1st month of Bunmei 9 (1477), Kageharu led about 2,500 horsemen in a sudden attack on the Igako camp and captured it. The camp had been the main base against the Koga kubō for eighteen years. The Uesugi leaders fled north during the night and withdrew to eastern Kōzuke. Dōkan, at Edo Castle, sent a messenger to Kageharu at Hachigata asking him not to attack his lord Uesugi Sadamasa and the others. Kageharu complied, and the Uesugi forces crossed the Tone River and entered places such as the Naba estate and Shirai Castle.

Many powers rose in response. They included Nagao Fusakiyo of Kannō Castle in Shimotsuke, Ōishi Norinaka of Ninomiya Castle in Musashi, Ōishi Iwami-no-kami of Kasai Castle in Shimōsa, and Ōmori Shigeyori and Mizorogi Masashige in Sagami. In southern Musashi, Toshima Yasutsune of Shakujii Castle and his younger brother Yasuaki of Nerima Castle sided with Kageharu and cut the line between Edo Castle and Kawagoe Castle.

Dōkan's campaigns: the Toshima and Yōdohara

Dōkan first moved against the Toshima of southern Musashi. He planned to attack Shakujii and Nerima on the 14th day of the 3rd month, but the plan was postponed because a flooded Tama River kept the Sagami troops from joining him. On the 18th day, the Sagami forces of the Ōgigayatsu Uesugi took Kageharu's Mizorogi and Koiso castles.

On the 13th day of the 4th month, Dōkan attacked Nerima Castle, defeated the Toshima at Ekodahara and killed Yasuaki. Yasutsune surrendered at Shakujii on the 18th, but because he did not dismantle the castle the surrender was judged false, and on the 28th Dōkan attacked Shakujii and took its outer enclosure. Yasutsune fled that night.

In the north, on the 8th day of the 5th month, the Uesugi side under Dōkan and others advanced as far as Yōdohara (present-day Yorii), then turned and met Kageharu's forces at Harigayahara (present-day Fukaya), winning a great victory. On the Uesugi side Ōishi Genzaemon-no-jō, a senior retainer of the Yamanouchi Uesugi, was killed; on Kageharu's side Nagano Tamenari, a leader of the Jōshū ikki, fell. Kageharu took position at Tomita and asked the Koga kubō Shigeuji for support. From then on the rebellion became part of the struggle between Shigeuji and the Uesugi.

In the 7th month of Bunmei 9, Shigeuji took the field at the request of Kageharu and others. His force numbered about 8,000 horsemen, joined by the Yūki, Nasu, Iwamatsu, Yanada and others. The Uesugi side fell back to Shirai Castle in northern Kōzuke, but in the 9th month came out and advanced to Katakai, while Dōkan moved separately to Aramaki and Hikita in an attempt to split Shigeuji's army. On the 14th day of the 11th month Kageharu and Shigeuji withdrew from their positions. Dōkan tried to pursue, but the late arrival of Nagao Kagetada cost him the chance. On the 2nd day of the 1st month of Bunmei 10 (1478), Uesugi Akisada proposed a truce to Shigeuji's side and it was concluded.

Shigeuji's campaign, the truce and Kageharu's fall

While Dōkan was in Kōzuke, Toshima Yasutsune rose again and built Hiratsuka Castle near Edo, cutting the link between Edo and Kawagoe. On the 25th day of the 1st month of Bunmei 10, when Dōkan closed on Hiratsuka, Yasutsune fled to Maruko and, after a fight on the 26th, shut himself up in Kozukue Castle. On the 10th day of the 4th month Dōkan took Kozukue and the Toshima were destroyed. Their former lands were confiscated by the Ōgigayatsu Uesugi, and many passed to Dōkan.

On the night of the 17th day of the 7th month, Shigeuji changed course to abandon Kageharu and asked Dōkan to attack him. Shigeuji is said to have wanted to return to Koga by making peace with the Uesugi side. In the early hours of the 18th Dōkan attacked Kageharu and won, and Hachigata Castle is thought to have fallen as well. Kageharu fled to Chichibu County. Shigeuji crossed the Tone River on the 23rd and returned to Koga Castle.

In the 9th month of Bunmei 10 Kageharu rose again in Musashi, entering a base of the Nagai before moving into Chichibu. In the 1st month of Bunmei 12 (1480) he advanced into Kodama County, but on the 20th he was met and beaten by Ōta Dōshin at the Ryūon-ji in Ogose, and shut himself up in the Hino fortress (Kumakura Castle) in Chichibu County. Shigeuji also showed signs of turning to Kageharu's support, but Dōkan, who joined Akisada in Chichibu on the 13th day of the 6th month, won over Moro Mikawa-no-kami to the Uesugi side and took the Hino fortress on the 24th. Kageharu was driven out of Musashi and fled to Kōzuke, and the rebellion based in Musashi was suppressed.

Afterward

In the 4th month of Bunmei 13 (1481), Kageharu settled at Ashikaga estate under Nagao Fusakiyo and tried to revive his cause by setting up Uesugi Norifusa, Akisada's adopted son, as head of the Yamanouchi Uesugi. On the 27th day of the 11th month of Bunmei 14, the Capital-Provinces Peace (tohi waboku) was concluded between Shigeuji and the shogunate, and Shigeuji was pardoned. Norifusa returned to Akisada, and Kageharu became a retainer of Shigeuji. The long turmoil in the Kantō headed toward its end. From the rising to the suppression in Musashi took about four years, and with the loss of the Igako camp the Uesugi side lost the main base it had held against the Koga kubō for eighteen years. The rebellion also marked the point at which the unity of the senior retainers who supported the Uesugi began to waver. In the 7th month of Bunmei 18 (1486), Dōkan was murdered by his lord Uesugi Sadamasa at the Kasuya residence.

Principal figures

- Nagao Kageharu: son of the chief retainer of the Yamanouchi Uesugi, Nagao Kagenobu. Resenting that the post went to his uncle Tadakage, he built Hachigata Castle and rose in Bunmei 8. He was driven from Musashi in the 6th month of Bunmei 12 and later became a retainer of Ashikaga Shigeuji. - Ōta Dōkan: lord of Edo Castle and senior retainer of the Ōgigayatsu Uesugi. After failing to reconcile Kageharu, he fought from front to front, against the Toshima, at Harigayahara and at the Hino fortress. - Nagao Tadakage: Kageharu's uncle, who became chief retainer of the Yamanouchi Uesugi after Kagenobu's death. - Toshima Yasutsune and Yasuaki: brothers who held Shakujii and Nerima castles in southern Musashi. They sided with Kageharu; Yasuaki was killed at Ekodahara, and Yasutsune perished with the Toshima house at the fall of Kozukue. - Uesugi Akisada and Uesugi Sadamasa: heads of the Yamanouchi and Ōgigayatsu Uesugi. They withdrew from the Igako camp and later faced Kageharu with Dōkan's support. - Ashikaga Shigeuji: the Koga kubō. He took the field at Kageharu's request, later abandoned him, and was pardoned in the Capital-Provinces Peace of Bunmei 14.