Nagao Kagenaka served as a bushō during the middle Muromachi period.  Kagenaka served as the kasai, or head of house affairs, of the Yamanouchi-Uesugi family.  Kagenaka was a key retainer of the family for five generations spanning from Uesugi Norisada (the sixth head) to Uesugi Fusaaki (the tenth head).  He was the deputy military governor of Kōzuke and Musashi provinces and as the lord of Shiroi Castle in the Gunma District of Kōzuke.  Together with Ōta Sukekiyo (Dōshin), these two men were called the “Twin Wise Men of the Kantō” forming the nucleus of the Uesugi army.  Grandsons included Nagao Kageharu (his lineal descendant) and Ōta Dōkan (grandchild from a daughter married into another family).

Service as a bushō of the Yamanouchi family

Kagenaka was born as the second son of Nagao Fusakage of the Kamakura-Nagao clan.  His mother was the daughter of Nagao Kiyokage of the Shiroi-Nagao clan, senior retainers of the Uesugi clan.  He became the adopted son-in-law of his uncle on his mother’s side, Nagao Kagemori.  In 1401, at the age of fourteen, owing to the death of his adoptive father, he inherited the headship of the Shiroi-Nagao clan.  Together with Nagao Tadamasa of the Nagao clan (the head of house affairs), he first served as a deputy to Uesugi Norisada.  In 1416, during the Uesugi Zenshū Conflict, he defeated the army of Uesugi Zenshū at Yuigahama and enabled the return of his lord, Uesugi Norimoto (the Kantō kanrei, or deputy shōgun of the Kantō) and Ashikaga Mochiuji (the Kamakura kubō) to Kamakura.

In 1438, after Mochiuji attempted to subdue Uesugi Norizane (Norimoto’s cousin, the eighth head of the Yamanouchi-Uesugi family and the deputy shōgun of the Kantō), triggering the Eikyō Conflict, Nagao Tadamasa allowed Norizane into Hirai Castle in Kōzuke and raised an army to subjugate Mochiuji.  In this battle, Kagenaka deployed as a lieutenant general and contributed to the capture of Mochiuji by Tadamasa.  He made further contributions at the Battle of Yūki.  In 1444, after Tadamasa left the position of the head of house affairs, Kagenaka assumed the same role for the Yamanouchi-Uesugi family.  This occurred upon request of Uesugi Kiyokata of the Jōjō-Uesugi family (the military governor of Echigo and younger brother of Norizane who also served as the head of the Yamanouchi-Uesugi family) in lieu of Norizane who took his children and absconded.

This same year, Kiyokata suddenly died and Norizane did not agree to a reinstatement from his retirement life so, following the end of the Kamakura kubō as an outcome of the Eikyō Conflict, the role of the deputy shōgun of the Kantō was vacated and governance of the Kantō stalled.  Kagenaka consulted with Ōta Sukekiyo (Dōshin), his son-in-law and the head of house affairs of the Ōgigayatsu-Uesugi, and then took out the eldest son of Norizane, Tatsutada (later known as Uesugi Noritada), and had him inherit the role of deputy shōgun of the Kantō.  Norizane, however, sought to have his cousin, Satake Sanesada, inherit the headship of the clan and, as a result, did not consent so Kagenaka excluded Norizane and Sanesada as he backed Noritada.

Conflict with Ashikaga Shigeuji 

A movement gained traction among Uesugi Fusatomo (the military governor of Echigo Province who succeeded Kiyokata) and generals in the Kantō to support the orphan of Ashikaga Mochiuji named Eijuōmaru (later known as Ashikaga Shigeuji) as the next Kamakura kubō, and the Muromachi bakufu consented.  In 1447, Eijuōmaru and Noritada went to Kamakura and Noritada was appointed as the deputy shōgun of the Kantō.  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 them received one of the characters from the name of Ashikaga Yoshishige (later known as Ashikaga Yoshimasa, the eighth shōgun of the Muromachi bakufu), adopted the name of Ashikaga Shigeuji, and formally became the fifth Kamakura kubō.

After Shigeuji assigned as close associates the orphans of bushō who martyred themselves during the Eikyō Conflict and the Battle of Yūki, opposition arose among the Uesugi clan and their band of retainers.

In 1450, an incident occurred by which Yanada Mochisuke (a retainer of the Koga kubō and lord of Mizuumi Castle in Shimōsa), acting upon orders of Shigeuji, seized the Nagao township in the Kamakura District of Sagami.  As stated in its name, this was the homeland of the Nagao clan and the Goryō Shrine located there was the center of worship for ancestors of the clan.  Infuriated by the news, Kagenaka and other members of the Nagao clan violently opposed Shigeuji but Shigeuji did not intend to return the land to them.

On 4/20, Kagenaka and Ōta Dōshin gathered 500 soldiers in Kamakura and attempted a revolt, but, after learning of these plans in advance, that same evening, Shigeuji escaped from Kamakura to hole-up in Enoshima.  The next day, the two armies clashed at Yuigahama.  The allied forces of the Nagao and Ōta suffered a major loss, while, unaware of the situation, Uesugi Noritada (Kagenaka’s lord), had the Obata clan and others deploy to rescue Shigeuji so Kagenaka and Dōshin fled to the Kasuya house of Uesugi Mochitomo, Dōshin’s lord and the prior head of the Ōgigayatsu-Uesugi family.  Although Noritada had no connection to the incident, after learning that soldiers from the Nagao and Ōta launched the attack, he was penitent.  This is known as the Battle of Enoshima.

Thereafter, Shigeuji returned to Kamakura and, in the tenth month, Noritada reverted to his position, and, upon his entreaty, the crimes of Kagenaka and others were forgiven.  Nevertheless, bushi on the side of Shigeuji and on the side of Noritada frequently seized the landholdings of members of the opposing camp.  As a result, Noritada and Mochitomo plotted to overthrow Shigeuji.  On 12/27 of Kyōtoku 3 (1455), on the evening when Kagenaka went out to worship while staying over at the Goryō Shrine in the Nagao township, Noritada was killed by Shigeuji’s army at Shigeuji’s residence.  At this time, in lieu of Kagenaka who had been demoted owing to the Battle of Enoshima, his brother-in-law, Nagao Sanekage, was appointed to serve as the head of house affairs for the Uesugi clan.  Sanegake, however, together with his lineal heir, Nagao Kagezumi, were slayed in a surprise attack by supporters of Shigeuji.

Showdown

Upon learning of the assassination of Noritada, Kagenaka returned to Kamakura and promptly set fire to the residence of the deputy shōgun and arranged for Noritada’s formal wife (the daughter of Uesugi Mochitomo) and other survivors to take refuge in the Kasuya house.  Upon his arrival at the Kasuya house, he held discussions with Mochitomo and other important members of the Uesugi family whereupon it was determined to usher in Uesugi Fusaaki (the younger brother of Noritada located in Kyōto) to serve as the next deputy shōgun of the Kantō.  Furthermore, a decision was made to subdue Shigeuji.  Kagenaka proceeded to enter his home province of Kōzuke.  Further, he summoned soldiers and sent a messenger to Uesugi Fusasada, the military governor of Echigo Province, to request a reinforcement army.  Meanwhile, he sent his lineal heir, Nagao Kagenobu, directly to Kyōto to notify the bakufu of the circumstances and received Fusaaki.  In the wake of the murders of Sanekage and Kagezumi, Kagenaka reverted to the vacant position of the head of house affairs.

In 1456, Shigeuji captured Kōzuke Province (the home base of the Uesugi clan) so he left Kamakura and entered the Kōan Temple in Fuchū in Musashi Province. Upon hearing this news, Kagenaka quickly gathered troops from Kōzuke and Musashi to launch an attack in Fuchū.  Members of the Uesugi deployed to converge with them.  On 1/21, these forces suffered an ignominious defeat at the Battle of Bubaigawara and lost some prominent bushō including Uesugi Akifusa (the head of the Ōgigayatsu-Uesugi) and Uesugi Noriaki of the Inugake-Uesugi family.  Kagenaka gathered together those who survived the battle and narrowly escaped to Oguri Castle in Hitachi Province, but, in the fourth month, Oguri Castle fell to Shigeuji’s army and Kagenaka fled to Kōzuke.  Imagawa Noritada hurriedly arrived in support of the Uesugi and ousted Shigeuji from Kamakura whereupon Shigeuji adopted the title of the Koga kubō and based himself at Koga Castle in Shimōsa Province.   These events occurred in connection with the Kyōtoku War.  Subsequent battles resulted in a division of the Kantō and, in 1459, during the Irako War in Kōzuke, Shigeuji’s army was defeated.

In 1463, Kagenaka died in Kamakura.  He was seventy-six years old.  He endeavored during his lifetime to promote the Uesugi family of the deputy shōgun of the Kantō and the Shiroi-Nagao clan.  His lineal heir, Nagao Kagenobu, inherited the role of the kasai, or head of house affairs, led the Yamanouchi-Uesugi family, and continued to engage in battles against Shigeuji.

Anecdote

In 1450, Kagenaka founded the Sōrin Temple where a wooden statue is enshrined.