Battle of Nyoigatake

如意ヶ嶽の戦い

Hosokawa Sumimoto

Yamashiro Province

Hosokawa Takakuni

Date:  6/17 of Eishō 6 (1509)

Location:  In the Awataguchi area of Nyoigatake in the Sakyō District of Kyōto

Outcome:  Hosokawa Sumimoto and Miyoshi Yukinaga led 3,000 forces to Nyoigatake and were surrounded by 20,000 to 30,000 allied forces under Hosokawa Takakuni and Ōuchi Yoshioki.  During a nighttime clash, Sumimoto and Yukinaga slipped away in the midst of a downpour and fled.

Commanders: Hosokawa Sumimoto, Miyoshi Yukinaga

Forces:  3,000

Losses: About 60 who were apprehended while attempting to flee the battle and later executed

Commanders: Hosokawa Takakuni, Ōuchi Yoshioki

Forces: 20,000 to 30,000

Losses:  Unknown

The Battle of Nyoigatake occurred at night on 6/17 of Eishō 6 (1509) in the area of Nyoigatake in the Sakyō District of Kyōto.  It is uncertain whether this escalated into a major conflict, was an attempt to launch another invasion of Kyōto, or an effort to destroy those attempting to return to Awa Province in Shikoku.

Prelude to the battle

In 1507, Hosokawa Masamoto, the deputy shōgun and de facto ruler of the bakufu, was assassinated in an event known as the Lord Hosokawa Incident (Hosokawa-dono no hen).  This owed to tensions within the Hosokawa clan concerning his designation of a successor, giving rise to a prolonged struggle among his three adopted sons.  This conflict was compounded by a rivalry between Ashikaga Yoshitane and Ashikaga Yoshizumi within the ruling Ashikaga family for the role of shōgun.  The combination of these multi-faceted struggles is known as the Eishō Disturbance (Eishō no sakuran) lasting from the time of Masamoto’s assassination in 1507 until the death of Hosokawa Takakuni at the Collapse at Daimotsu (Daimotsu kuzure) in 1531.

Following Masamoto’s killing by a faction that supported Hosokawa Sumiyuki, another one of the adopted sons named Hosokawa Sumimoto, along with Miyoshi Yukinaga, escaped to Kōka in Ōmi Province.  Soon thereafter, Sumimoto and Yukinaga led attacks in Kyōto resulting in the deaths of many supporters of Sumiyuki. Sumimoto seized the role of head of the Hosokawa clan while Yukinaga  held the distinction of serving as his close associate.

In the midst of this chaos, Ashikaga Yoshitane, the former shōgun who had earlier been ousted by Masamoto in an event known as the Meiō Political Incident (Meiō no seihen), relied upon Ōuchi Yoshioki, the sengoku daimyō from Suō Province, in an effort to march upon Kyōto.  Upon learning of these developments, Sumimoto received support from his grandfather, Hosokawa Naruyuki, along with Hosokawa Takakuni (another one of Masamoto’s adopted sons), and devised a plan to reconcile with Yoshioki. Takakuni, however, had his own plans to take over the clan, and a tacit understanding with Yoshioki. On 3/17 of 1508, Takakuni fled Kyōto under the pretext of visiting the Ise Grand Shrine, and received protection from Nitsuki Takanaga, the military governor of Iga Province.

On 4/9, after Takakuni’s exit from Kyōto, kokujin, or members from clans of local influence, primarily from Sumimoto’s domain in Settsu and Tanba provinces, aligned themselves with Takakuni owing to dissatisfaction with Yukinaga.  Meanwhile, Sumimoto and Yukinaga interpreted the approach of the Ōuchi army as an impending threat, causing them to torch their residences and again flee for safety to Ōmi Province.  On 4/10, Takakuni entered Kyōto.  On 6/9, Ashikaga Yoshitane then came to the capital from Sakai and, on 7/1 of 1508, reclaimed his position as shōgun.  Takakuni became the kanrei, or deputy shōgun, while Yoshioki became the kanreidai, or vice-deputy shōgun.  By this means, Takakuni banished Sumimoto and took over as lord of the Hosokawa clan.

Thereafter, supporters of Sumimoto including Ikeda Sadamasa, a kokujin from Settsu, was killed, while Akutagawa Bingo no kami died in a typhoon.  Unable to procure conscripts in Ōmi, Sumimoto found himself in an increasingly desperate situation.

Details of the battle

In the sixth month of 1509, Sumimoto and Yukinaga sought to break out by crossing Lake Biwa, traversed the Ozeki Pass, and, on 6/17, set-up an encampment with 3,000 forces in Nyoigatake.  In response, the allied forces of Takakuni and the Ōuchi numbering between 20,000 to 30,000 men took positions to surround Nyoigatake.  That night, the opposing forces clashed during a downpour, while Sumimoto and Yukinaga safely disappeared amidst the rain to Awa Province.  As such, the bid by Sumimoto and Yukinaga to capture Kyōto ended in failure, but threats remained. Those included Ashikaga Yoshizumi, who pined for his former role as shōgun.  Takakuni’s arrival in the capital had caused Yoshizumi to flee, and he procured refuge at Okayama Castle in Ōmi under the Kunori clan.  On 10/2, Takakuni and Yoshioki, however, directed an army to attack Okayama Castle.

Scale of the battle

There is a view that Nyoigatake was not a major battle.  Sumimoto and Yukinaga commanded only about 3,000 men.  Given Yukinaga’s military acumen, it is unlikely that he would make a bid to capture Kyōto with such a limited force.  The goal may have been to break out of a stalemate and return safely to Awa.  According to several accounts, Sumimoto and Yukinaga took advantage of a downpour at night to flee.  Meanwhile, about sixty fleeing soldiers were apprehended in the environs of Kyōto and executed.

The aftermath

After the battle, Miyoshi Nagahide, the son of Yukinaga, separated from his father and fled to Ise Province, but was caught by Takakuni and killed in Ujiyamada.  Based on many sources, Sumimoto fled safely to Awa, but there is another view that he fled on 10/2 from the Battle of Okayama Castle.