Date: Fourth month of Eishō 9 (1512) to seventh month of Eishō 11 (1514)
Location: Shimotsuke Province
Outcome: Following years of friction that escalated into military conflict, Utsunomiya Shigetsuna defeated his rival in Haga Takakatsu. However, their successors produced a reverse outcome when Haga Takatsune defeated Utsunomiya Tadatsuna, accelerating the decline of the clan.
The Utsunomiya Disturbance occurred from the fourth month of Eishō 9 (1512) to the seventh month of Eishō 11 (1514). This involved an internal dispute known as the Eishō Discord (Eishō no naikō) that escalated into military conflict among members of the Shimotsuke-Utsunomiya clan in Shimotsuke Province. In particular, the Haga clan vied for power with their lords, the Utsunomiya clan. In addition to this power struggle, the two clans backed opposing sides in a conflict over succession of the Koga kubō (the Kantō branch of the ruling Ashikaga shōgun family), with the Haga backing Ashikaga Masauji and the Utsunomiya backing his son, Ashikaga Takamoto.
In the Kyōtoku War, a major conflict that spanned over twenty-eight years in the Kantō, the Utsunomiya clan was traditionally in a position aligned with the Ashikaga shōgun family. Nevertheless, because the Kantō kubō moved its base to Koga Castle located near Utsunomiya Castle, political and military pressures caused repeated acts of betrayal during the course of the war. To cope with the turbulence, certain branches of the Utsunomiya clan as well as bushi from less prominent families in the central parts of Shimotsuke sought to strengthen their ties to the Utsunomiya as the most influential clan in the province and came under their governance. This, in turn, however, led to conflicts with longstanding retainers including the Haga clan, the chief retainer who served as the deputy military governor when the Utsunomiya were the military governors of Kōzuke Province as well as clans such as the Shionoya, the Minagawa, and the Mibu who were gaining influence, leading to instability within the Utsunomiya family.
In 1477, after Utsunomiya Shigetsuna became the head of the clan, he endeavored to restore the authority of the leader. In fact, however, Haga Kagetaka held the actual power. After the demise of Kagetaka in 1497, his son, Haga Takakatsu continued to possess the authority. In lieu of Shigetsuna, Takakatsu ordered exemptions from special levies, and Takakatsu’s seal appears jointly on documents issued by Shigetsuna during this period.
In 1506, Ashikaga Masauij (the Koga kubō) came into conflict with his son, Ashikaga Takamoto, in regard to succession issues in an event known as the Eishō Conflict. As the father-in-law of Takamoto, Shigetsuna supported him as the successor. Haga Takakatsu, however, as the holder of power in the family, disagreed and supported Masauji instead, rupturing the Utsunomiya family.
In the fourth month of 1512, Shigetsuna murdered Takakatsu, causing the Haga clan to revolt. This revolt is known as the Utsunomiya Disturbance. In the same year, Shigetsuna transferred his position as head of the clan to his eldest son, Tadatsuna. The timing of the succession is uncertain, but the oldest document issued by Tadatsuna in his role as the head of the clan was in early spring of the same year, so Takakatsu may have been involved prior to his demise.
Having eliminated Takakatsu, Shigetsuna reclaimed authority over the family and served as a guardian of the youthful Tadatsuna while endeavoring to suppress the Haga clan. Owing to their period in power, the influence of the Haga was comparable to the Utsunomiya. Based on support from Takamoto (his son-in-law) and Oda Masaharu (a daimyō and supporter of Takamoto), from 1514, Shigetsuna actively went on the offensive, and by the summer of that year, suppressed the rebellion by the Haga clan. Thereafter, despite attacks from the Satake and Iwaki clans who favored Masauji, Shigetsuna and Tadatsuna defeated their opponents at the Battle of Takebayashi in late 1514 and the Battle of Nawazuri in the summer of 1516. The Utsunomiya thereby overcame the immediate crisis.
After the rebellion, Shigetsuna spared the lives of Haga Takatsune (Kagetaka’s son and younger brother of Takakatsu) and Haga Takataka (Kagetaka’s younger brother) and detained them in Utsunomiya Castle. He then had his youngest son and still an infant, Okitsuna, become the successor to the Haga clan, and had his younger brother, Shionoya Takatsuna, manage the Haga landholdings. Later in 1516, as though having assured himself that the chaos within the Utsunomiya family was settled, he then died of illness.
Owing to the death of Shigetsuna, Tadatsuna became the head of the Shimotsuke-Utsunomiya in name and in fact. He strove to expand the organization and influence of the clan, but not everyone in the family obeyed Tadatsuna. In 1523, Haga Takatsune went to Yūki Masatomo, who assisted Takatsune by directing troops toward to the Utsunomiya. Tadatsuna’s forces intercepted them, but incurred a major loss at the Battle of Saruyama. A faction opposed to Tadatsuna coordinated with Takatsune by occupying Utsunomiya Castle, causing Tadatsuna to flee to Kanuma Castle. With the backing of the Yūki clan, Takatsune advocated for Tadatsuna’s youngest brother, Haga Okitsuna, to become the new head of the Utsunomiya clan, while he succeeded in reclaiming the status as head of the Haga clan. Thereafter, a dejected Tadatsuna died of illness, while next, a now mature Okitsuna came into conflict with Takatsune. From the beginning of the Tenbun era (1532 to 1555), Takatsune incarcerated and then killed Okitsuna, whereupon he backed Hisatsuna (an older brother of Okifusa) who had earlier become a monk. Later, Hisatsuna then killed Takatsune, while confrontation between the Utsunomiya and Haga clans persisted in the family over the Eishō, Daiei, and Tenbun eras, accelerating the decline of the Utsunomiya clan.