Lifespan: Unknown to Unknown
Title: Assistant Captain of the Right Division of the Imperial Guards
Bakufu: Muromachi – Secretary of the Kantō
Lord: Ashikaga Yoshimasa
Father: Shibukawa Yoshitoshi (or Shibukawa Mitsuyori)
Wife: Daughter of the Yamana clan
Children: Shiba Yoshikado
Adopted Children: Yoshitaka
Shibukawa Yoshikane served as a bushō from the mid- to late-Muromachi period. Yoshikane accompanied Ashikaga Masatomo, the Horigoe kubō, as a deputy after Masatomo was dispatched to the Kantō by the Muromachi bakufu to bring to an end the Kyōtoku War. He then came into conflict with the Ōgigayatsu-Uesugi clan and lost his position.
Yoshikane was born as the son of Shibukawa Yoshitoshi, a shugo daimyō and the Kyūshū tandai, or Commissioner of Kyūshū. The details of the first half of his life are uncertain. In 1428, his father, Yoshitoshi, retired but did not transfer the role of Kyūshū tandai to Yoshikane. Instead, Yoshitoshi’s cousin, Shibukawa Michinao, became the next Kyūshū tandai.
Service as a deputy to Ashikaga Masatomo
In 1435, Ashikaga Masatomo was born as the fourth (illegitimate) son of Ashikaga Yoshinori, the sixth shōgun. He was older than Ashikaga Yoshimasa but treated as a younger brother because Yoshimasa’s mother came from the Hino, a family of a noble lineage who had intermarried with the Ashikaga shōgun family for generations. Masatomo was raised as a monk from an early age, becoming the head of the Kōgen-in, a sub-temple of the Tenryū Temple, and adopting the name of Seikyū.
On 12/19 of Chōroku 1 (1457), Seikyū returned to secular life upon orders of Yoshimasa, receiving one of the characters from Yoshimasa’s name and adopting the new name of Masatomo. Several days later, he departed Kyōto and arrived at Onjōji in Ōmi Province. On 5/25 of Chōroku 2 (1458), he was given a flag of conquest and headed toward the Kantō. He then arrived between 5/25 and 8/13 in Horigoe in Izu Province.
Yoshikane (the secretary of the Kantō) and Uesugi Noritomo accompanied Masatomo as his deputies. Yoshikane may have been chosen because the Shibukawa clan had a cadet family in the Kantō and, as members of the Ashikaga clan, were of prominent status. According to one account, Yoshikane was already in the Kantō by 1457 and, in his capacity as the Kantō tandai, or Commissioner of Kantō, endeavored to amass troops but could not draw sufficient numbers so requested Yoshimasa to dispatch a member of the Ashikaga family which was Masatomo.
Masatomo was dispatched to serve as the Kamakura kubō with the official sanction of the bakufu. However, the prolonged struggle between the bakufu and Ashikaga Shigeuji, the influential Koga kubō, in the Kyōtoku War prevented Masatomo from entering Kamakura. Consequently, around the sixth month, he settled in Horigoe in Izu Province. Around the time that Yoshimasa dispatched Masatomo, he ordered daimyō from provinces in the Kantō including Mutsu, Dewa, Kai, and Shinano to deploy for a large-scale offensive to overthrow Shigeuji in favor of Masatomo.
In 1458, Masatomo established an administration known as the Horigoe kubō based in in Horigoe in Izu Province. In the eighth month, a bushō named Iwamatsu Mochikuni on the side of Ashikaga Shigeuji defected to the bakufu. Three months prior to traveling to the Kantō, Mochikuni sent a letter pledging allegiance demanded by Masatomo and Yoshikane added a note of introduction. From around this time, Yoshikane became a secretary to Masatomo. Nevertheless, the Horigoe administration continued to contend with a deficit of military power so the bakufu ordered Shiba Yoshitoshi to deploy to the Kantō to subdue Shigeuji while Yoshikane was permitted to mobilize members of the Shibukawa clan. In 1459, Shibukawa Toshiaki (Yoshitoshi’s younger brother and Yoshikane’s uncle) died of illness in Asakusa in Musashi Province.
Yoshitoshi came into conflict with Kai Jōchi, triggering the Battle of Chōroku from 1458 to 1459. Earlier, Yoshimasa had the two parties settle but tensions persisted and escalated into a battle. In the eleventh month, Yoshitoshi obeyed orders to deploy again. In the fifth month of 1459, he led the army to Echizen Province and attacked Kanagasaki Castle (aligned with the Kai) but suffered a major defeat. An enraged Yoshimasa removed Yoshitoshi from the line of succession and designated his three-year-old son, Matsuōmaru (later known as Shiba Yoshihiro), to be the next head of the Shiba clan. In the tenth month, in the absence of the Shiba clan, the bakufu army battled against the Koga kubō at Ōta-no-shō near the frontline base at Ikakkojin but were defeated so the effort to subdue Shigeuji failed. This is known as the Irako War. During this time, Yoshitoshi fled for the protection of Ōuchi Norihiro of Suō Province. Meanwhile, Jōchi died in the eighth month of 1459.
Relationship with the Shiba clan
In the first month of 1460, Imagawa Noritada, a daimyō on the side of the bakufu, returned to Suruga Province. In the fourth month, the Kokusei Temple that served as a base in Horigoe was burned down by the Koga kubō so Masatomo moved the base to the Horigoe palace. After Noritada returned to Suruga, owing to the outcome of the Battle of Chōroku, the conflict that flared in the prior year in Tōtōmi Province was connected to the invasion of Tōtōmi by Imagawa Norimasa, a relative of Noritada. The Shiba clan dispatched Kai Toshimitsu and Asakura Takakage to Tōtōmi to engage in suppression activities and also deployed troops to the Kantō. Seeking to exploit an opportunity, Masatomo leveraged the Shiba army in a bid to enter Kamakura but, in the eighth month, was halted by Yoshimasa.
Messengers from the Kantō arrived in the capital to appeal for the further mobilization of forces to address the lack of military power wielded by the Horigoe administration. In 1461, Matsuōmaru was removed from the line of succession and Yoshikane’s son, Yoshikado, succeeded to the headship of the Shiba clan demonstrating that Yoshimasa responded to the wishes of the Horigoe administration. Yoshikado was then known as Shiba Yoshikado.
Loss of position
In 1461, Uesugi Noritomo who, together with Yoshikane, supported Masatomo, took his own life. He was succeeded by his son, Uesugi Masanori, who traveled from the capital to the Kantō. Meanwhile, Ōta Sukekiyo, the head of house affairs for the Ōgigayatsu-Uesugi family, retired.
In 1462, a rumor circulated of a rebellion by Uesugi Mochitomo. This may have been connected to a dispute with Masatomo in regard to the designation of rice fields for the provision of food supplies to the military. As a result, Mochitomo was subject to questioning by Yoshimasa. Rather than Mochitomo, senior retainers of the Ōgigayatsu-Uesugi family including Miura Tokitaka, Ōmori Ujiyori and Ōmori Saneyori (father and son), and Chiba Sanetane took responsibility for the dispute by retiring and Yoshimasa ordered Masatomo to protect Mochitomo. Nevertheless, these developments significantly diminished Mochitomo’s influence. There is a theory that this was orchestrated by Yoshikane from behind the scenes. Mochitomo subsequently aimed to settle with Shigeuji in a bid to counter Masatomo but died in 1467 at the age of fifty-two.
Around the seventh month of the prior year, Mochitomo’s activities as the military governor of Sagami were halted and the Horigoe administration seized the powers of governance. These events occurred in the wake of the death of Uesugi Noritomo and retirement of Ōta Sukekiyo in 1461.
References to Yoshikane’s activities cease from 1462 while letters from Yoshimasa to Yoshikane also ceased from around this time. In response to the conflict between the Horigoe administration and powerbrokers in the Kantō, the bakufu stood on the side of the Ōgigayatsu-Uesugi family and took steps to remove Yoshikane.
After the loss of his position, Yoshikane’s subsequent movements are unknown. He is said to have retired to the Warabi township while his adopted son, Shibukawa Yoshitaka, became the lord of Warabi Castle.
Following the removal of Yoshikane, Yoshimasa considered another mobilization of the Shiba clan and attempted to have Yoshitoshi resume the position as the head of the clan. Kai Tsuneharu died so Yoshitoshi made another attempt to assemble an expedition army but was opposed by Shiba Yoshikado whereupon he turned to his father-in-law, Yamana Sōzen, for support. On 9/6 of Bunshō 1 (1466), Ise Sadachika and Kikei Shinzui, close associates of Yoshimasa, were ousted by daimyō opposed to them in an event known as the Bunshō Political Incident. This later escalated into the Ōnin-Bunmei War.
In lieu of Yoshikane, the descendants of his uncle, Toshiaki, were treated as members of the goikka – three clans (the Kira, the Shibukawa, and the Ishibashi) on a par with the family of the deputy shōgun of the Muromachi bakufu having rights of succession to the role of the shōgun. Nevertheless, after the Ōnin-Bunmei War, this lineage also fell into decline and from the Eishō era (1504 to 1521) there are no further records concerning the movements of the Shibukawa clan from Kyōto.