Revolt of Kunohe Masazane

九戸政実の乱

Toyotomi Clan

Mutsu Province

Kunohe Clan

Date:  3/13 to 9/4 of Tenshō 19 (1591)

Location:  Kunohe Castle in the Nukanobu District of Mutsu Province

Synopsis:  In 1582, the deaths in close succession of Nanbu Harumasa and his son and heir, Nanbu Harutsugu, gave rise to an intense succession struggle between Nanbu Nobunao (the son of a retainer named Ishikawa Takanobu) and the Kunohe clan, powerful members of the Nanbu family who served in the vanguard of their military.  In pursuit of his desire to become the twenty-sixth head of the Nanbu clan, Nobunao outmaneuvered Kunohe Sanechika.  This outcome angered Sanechika’s older brother, Kunohe Masazane, who also held grievances toward the Toyotomi administration for recognizing Nobunao as the successor to the clan.  The ensuing revolt caused Hideyoshi to dispatch a powerful army that forced the surrender of Masazane at Kunohe Castle and resulted in his execution.

Lord:  Toyotomi Hideyoshi

Commanders:  Nanbu Nobunao, Gamō Ujisato, Horio Yoshiharu, Ii Naomasa

Forces:  60,000

Losses:  Unknown

Commanders:  Kunohe Masazane, Kunohe Sanechika, Kushibiki Kiyonaga, Shichinohe Iekuni

Forces:  5,000

Losses:  Kunohe Castle and Kunohe army decimated

The Revolt of Kunohe Masazane occurred from 3/13 to 9/4 of Tenshō 19 (1591) with the final battle at Kunohe Castle in the Nukanobu District of Mutsu Province.

This event arose when Kunohe Masazane, a powerful member of the Nanbu clan, launched a rebellion against Nanbu Nobunao (a sengoku daimyō and the twenty-sixth head of the Nanbu clan) and the Oushū Retribution conducted by the Toyotomi administration in the Ouu region.

Background

Nanbu Harumasa, the twenty-fourth head of the Nanbu clan, ushered in an era of peak prosperity.  His death from illness in 1582 triggered a succession struggle that divided the family.  Prior to this event, Harumasa had been in a series of conflicts with members of the Nanbu family including with the influential Kunohe clan as well as with an alliance led by Takko (Ishikawa) Nobunao along with Kita Nobuchika and Minami Nagayoshi.  Less than three weeks after the demise of Harumasa, his son, Nanbu Harutsugu, was assassinated shortly after succeeding Harumasa as the head of the Sannohe-Nanbu family.  Harutsugu was only thirteen years old.  This gave rise to a succession dispute between the Kunohe family and the Takko (Ishikawa) family to determine the next head of the main branch of the Nanbu family.  Takko (Ishikawa) Nobunao pushed aside Kunohe Sanechika and maneuvered himself into the role as the head of the Sannohe-Nanbu and, by becoming the head of the clan, angered Kunohe Masazane, the older brother of Sanechika, severing their relationship.

The Nanbu were comprised of a union of family members led by the Sannohe-Nanbu in addition to, among others, the Hachinohe, the Kunohe, the Kushibiki, the Ichinohe, and the Shichinohe clans in the district.  On 7/27 of Tenshō 18 (1590), a sealed order from Toyotomi Hideyoshi provided official recognition of Nobunao as the head of the Sannohe-Nanbu as the main branch of the Nanbu clan.  He was thereby included among the early modern daimyō under the Toyotomi administration.  Other powers in the region, even if influential, did not receive recognition of their independence and were requested to serve as members or retainers of the main branch of the Nanbu family.  Opposition to this demand led the Kunohe clan into fierce conflict with Nobunao.

The Oushū Retribution and outbreak of uprisings

In the sixth month of 1590, while Nanbu Nobunao was away from his base leading 1,000 soldiers on deployment for the Conquest of Odawara and, thereafter, for the Oushū Retribution, supporters of the Kunohe clan attacked Minami Moriyoshi on the side of the Sannohe-Nanbu clan.  The ensuing death in battle of Moriyoshi raised tensions among the Nanbu family.  Around this time, the Toyotomi army sent to enforce the actions comprising the Oushū Retribution launched an offensive in the area of Hiraizumi.  These forces took control of the castles of landowners such as the Ōsaki, the Kasai, and the Kurokawa who chose not to participate in the Conquest of Odawara and then conducted land surveys.  Magistrates of the Toyotomi administration including Asano Nagamasa assigned district governors and representatives and then withdrew their forces.

Beginning in the tenth month of 1590, after the Toyotomi forces returned to their respective provinces, dissatisfaction with the measures taken in the Oushū Retribution led to a series of large-scale uprisings erupting across Mutsu Province, including the Kasai-Ōsaki Uprising, the Senboku Uprising, and others.  Nanbu Nobunao sent forces to the Waga-Hienuki Uprising, but all that he could achieve was to rescue Asano Nagamasa who was surrounded at Toyagasaki Castle (the original base of the Hienuki clan) and bring him to the base of the Nanbu clan at Sannohe Castle.  Owing to the accumulation of snow, he could not dispatch an army to suppress the uprising.

Rebellion by the Kunohe forces

In the midst of an unstable situation, as the new year arrived in 1591, the Kunohe clan refused to visit Sannohe Castle to offer new year’s greetings, making clear their rebellious intent against the main branch of the Nanbu family.  Asano Nagamasa, the official for the Toyotomi administration based at Sannohe Castle, sent a letter dated 2/28 to Irobe Nagazane, a senior retainer of Uesugi Kagekatsu stationed at Ōmori Castle on the western end of the Yokote Basin stating “There is a group of samurai with a rebellious intent stirring chaos in the Nukanobu District, the group has antipathy toward central authority and harbors resentment toward Nanbu Nobunao for yielding to the Toyotomi.  Without the dispatch of Toyotomi forces, Nobunao will face a dire situation.”  Another letter addressed to Nagazane on the same day from Nobunao stated “We are imposing losses on the rebels but it is necessary to send the Toyotomi forces.”

In the third month, the forces commenced hostilities by attacking Kushibiki Kiyonaga at Tomabechi Castle, a retainer of the Nanbu supporting the Kunohe.  Masazane then mobilized 5,000 troops to rebel, attacking in succession the surrounding castles and mansions of those who would not cooperate with the Kunohe.  A letter dated 3/17 from Asano Nagamasa to Irobe Nagazane states “The Kunohe and Kushibiki rebelled so remain vigilant.  A rumor is circulating that the Toyotomi army will come so the rebels are refraining from operations.”

As the original vanguard of the Nanbu army, the Kunohe forces were tough in battle.  The Sannohe-Nanbu, with the support of the Kita, the Nakui, the Noda, and the Jōhōji engaged in defense, but, by leveraging the uprisings within the Nanbu territory, the Kunohe forces grew in strength.  Moreover, some of the retainers of the Nanbu were ambivalent, believing that even if they prevailed in the family conflict, there would be no reward, causing Nobunao to struggle against the rebellion.  Ultimately, Nobunao realized that he could not subdue the Kunohe forces on his own, so he sent his son, Nanbu Toshinao, and Kita Nobuchika as messengers to Hideyoshi to request in a meeting on 6/9 that Hideyoshi’s army subjugate them.  Upon orders of Hideyoshi, Toyotomi Hidetsugu served as the commander-in-chief of an army led by Gamō Ujisato, Asano Nagamasa, and Ishida Mitsunari that commenced a march toward Oushū for the purpose of conquering the rebel forces of the Kunohe.  In an army swelling to over 60,000 men, others joining the effort included Onodera Yoshimichi, Tozawa Masamori, Akita Sanesue, and Ōura Tamenobu.

Second deployment by the Toyotomi army

In addition to those of the Kunohe, Oushū witnessed other large-scale uprisings so, with the aim of suppressing all of the resistance, on 6/20, Hideyoshi issued orders for the formation of an army to re-deploy to the region.  At the gateway to Shirakawa, Toyotomi Hidetsugu served as commander-in-chief of an army of 30,000 soldiers in addition to Tokugawa Ieyasu; at the gateway to Senboku, Uesugi Kagekatsu and Ōtani Yoshitsugu deployed; in the direction of Tsugaru, Maeda Toshiie and Maeda Yoshinaga deployed; and, at the gateway to Sōma, Ishida Mitsunari, Satake Yoshishige, and Utsunomiya Kunitsuna deployed.  Date Masamune, Mogami Yoshiaki, Onodera Yoshimichi, Tozawa Mitsumori, Akita Sanesue, and Tsugaru Tamenobu were directed to serve under the command of these leaders.

While suppressing the uprisings, the Toyotomi army marched north, converging with Gamō Ujisato and Asano Nagamasa.  By the end of the eighth month, the forces approached the Nanbu territory.  On 8/23, a bushō named Kozuya Settsu-no-kami under the command of Kunohe Masazane led fifty troops and launched a surprise attack against the Toyotomi forces at Mino-Kizawa, killing 480 men.  This served as the opening act of the conflict.  On 9/1, Anetai and Nesori castles which served as front-line bases for the Kunohe forces were toppled.  Kunohe Masazane holed-up in Kunohe Castle and, on 9/2, an army of 60,000 forces laid siege to the castle.

Siege of Kunohe Castle

Kunohe Castle was a natural fortress, protected by rivers on three sides including the Mabechi River on the west, the Shiratori River on the north, and the Nekobuchi River on the east.  Gamō Ujisato and Horio Yoshiharu were positioned on the south facing the entrance to the castle; Asano Nagamasa and Ii Naomasa were across the Nekobuchi River to the east, Nanbu Nobunao and Matsumae Yoshihiro were across the Shiratori River to the north; and Tsugaru Tamenobu, Akita Sanesue, Onodera Yoshimichi, and members of the Twelve Heads of Yuri were positioned across the Mabechi River to the west.  Commanding only a small force, Kunohe Masazane fought valiantly against the forces surrounding the castle, but one-half of the defenders were killed in action.  Nagamasa called upon Satten, the high priest of the Hōchōzan-Chōkō Temple (the family temple of the Kunohe) to serve as a messenger, convincing Masazane that if he vacated the castle then the lives of those remaining would be spared.  After accepting these terms, Masazane left matters to his younger brother, Kunohe Sanechika, and, on 9/4, appearing in white clothing as though having entered the priesthood, surrendered to the Toyotomi army.  Those joining him included Shichinohe Iekuni, Kushibiki Kiyonaga, Kuji Naoharu, Maruko Mitsutane, Ōsato Chikamoto, Ōyu Masatsugu, and Ichinohe Sanetomi.

An order jointly signed by representatives of the Asano, the Gamō, the Horio, and the Itō instructed peasants and others to return to their homes along with other post-war measures.  As though the promise to spare lives was scrapped, the victors corralled everyone in the castle below Kunohe Masazane into the outer citadel, slaughtered them, and set fires all around.  Mitsukage was exposed to the elements for three days and nights.  The bones of women slayed have been exhumed from the former location of the outer citadel of Kunohe Castle.  Meanwhile, the ringleaders of the revolt including Masazane were gathered and executed at Misako in the Kurihara District of Mutsu.

Aftermath

After these events, Hideyoshi ordered Gamō Ujisato to fortify Kunohe Castle and the town below to prepare against the threat posed by remnants of the Kunohe clan, and then transferred the premises to Nanbu Nobunao.   Nobunao moved the base of the Nanbu family from Sannohe Castle to Kunohe Castle and changed the name of the location to Fukuoka.

This revolt marked the end of organized resistance toward the Toyotomi administration enabling Hideyoshi to achieve the unification of Japan.  Meanwhile, the Nanbu clan used the opportunity to deepen their relations with the Gamō clan.  The adopted daughter of Gamō Ujisato known as Otake-no-kata wed Nanbu Toshinao.  On this occasion, a decorated helmet with wings known as a kawari-kabuto was presented as a souvenir to the Nanbu clan.

Ujisato and Asano Nagamasa recommended to Nobunao that he moved his base southward.  This served as the reason for the construction of Morioka Castle.  The descendants of Nakano Yasuzane (Masazane’s younger brother) adopted the Nakano surname and, together with the Hachinohe and Kita clans, served as chief retainers of the Nanbu family for generations, with the Nakano clan comprising one of the Three Families of the Nanbu.