Siege of Uezakura Castle
Date: From the sixth month to 7/16 of Genki 4 (1573)
Location: The environs of Uezakura Castle in Awa Province
Synopsis: Following internal conflicts triggered in part by illicit liaisons by senior members of the clan with a consort named Koshōshō, Shinohara Nagafusa shut himself in Uezakura Castle, inviting an attack led by Sogō Masayasu that ended in his demise.
Lord: Miyoshi Nagaharu
Commanders: Sogō Masayasu
Forces: 10,000 (7,000 forces led by Sogō Masayasu, including from the Kōzai and Kagawa clans of Sanuki Province and from Awaji Province; 3,000 forces from Kii Province)
Losses: Approximately 3,000 killed in total from both sides
Commanders: Shinohara Nagafusa
Forces: Approximately 1,500
Losses: Uezakura Castle burned, Shinohara Nagafusa and Shinohara Nagashige (father and son), and approximately 3,000 killed in total from both sides
The Siege of Uezakura Castle occurred from the sixth month to 7/16 of Genki 4 (1573) in the environs of Uezakura Castle in Awa Province in Shikoku. This conflict was waged by Miyoshi Nagaharu, together with Hosokawa Saneyuki (the military governor of Awa) to eliminate Shinohara Nagafusa, a retainer and the lord of Uezakura Castle.
Miyoshi Nagayoshi, the real holder of power in the Muromachi bakufu, was vanquished by Miyoshi Jikkyū, the younger brother of Hosokawa Mochitaka, the lord of Awa Province. Jikkyū then became the lord of Awa and claimed Shōzui Castle. In the third month of 1562, the allied forces of Hatakeyama Takamasa and Rokkaku Yoshikata (representing the faction supporting Ashikaga Yoshiteru) clashed against the allied forces of Jikkyū and Shinohara Nagafusa at the Battle of Kumeda. Jikkyū was killed in this battle. Thereafter, Jikkyū’s eldest son, Miyoshi Nagaharu, succeeded him as the lord of Awa, while his second son, Sogō Masayasu, was adopted by the Sogō clan and became the lord of Sogō Castle in Sanuki Province. At this time, however, Nagaharu was eight years old, so Shinohara Nagafusa of Uezakura Castle, Shinohara Jiton of Kizu Castle, and Akazawa Sōden of Banzai Castle supported him to govern the province and conduct the affairs of the Miyoshi administration. In particular, Nagafusa brought together the band of retainers of the Miyoshi family and enacted provincial laws, becoming a central figure in the Miyoshi clan.
Thereafter, Nagafusa engaged in numerous battles. In the ninth month of 1570, Nagafusa fought against the army of Oda Nobunaga at the Battle of Noda and Fukushima Castles. In the fifth month of 1571, he fought against the Mōri army at Kojima in Bizen Province, and, in the ninth month, he joined an attack against Wada Koremasa at Takatsuki Castle in the Battle of Shiraikawara.
Hosokawa Mochitaka (the military governor of Awa) had a consort named Koshōshō who was admired as a beautiful woman. While Mochitaka was still living, she entered into an illicit relationship with Miyoshi Jikkyū, later becoming Jikkyū’s wife and bearing two children, Miyoshi Nagaharu and Sogō Masayasu. There is a theory that she was also the mother of Hosokawa Saneyuki. From around the time that Nagafusa returned to Awa, Koshōshō became intimate with Shinohara Jiton of Kizu Castle, shunning Nagafusa. After being remonstrated for his illicit relationship with Koshōshō and having his powers trimmed, he became upset. Perhaps because he became tired of the situation, on 3/22 of Genki 4 (1573), Nagafusa left Shōzui Castle and shut himself in Uezakura Castle. However, this may have been viewed by those around him as a betrayal or plan to attack them, so Miyoshi Nagaharu and Hosokawa Saneyuki called together soldiers with the aim of eliminating Nagafusa.
Course of events
Upon orders of Miyoshi Nagaharu, Sogō Masayasu, as commander-in-chief, led an army of 7,000 soldiers including Mori Hida-no-kami, Izawa Ukon Taifu, the Kagawa clan of Sanuki Province, the Kōzai clan, and soldiers from Awaji Province, in addition to 3,000 soldiers from Kii Province and, in the sixth month of 1573, attacked Banzai Castle, the base of Akazawa Sōden who from the beginning had been on friendly terms with Shinohara Nagafusa. In parallel, forces headed toward Uezakura Castle. Having detected the approaching army, Nagafusa positioned 1,500 soldiers in the Zennyū and Tōzen temples that served as outer citadels, and confronted the enemy forces across the Yoshino River. Prior to this time, Nagafusa had performed deep excavation of the river which flowed with a strong current, so it could not easily be traversed. The conflict began with guerilla tactics and then evolved into a blockade, with a tightening siege. In addition to the pressure on the castle, supply lines for armaments and provisions were severed, making it difficult for the defenders to hold the castle. The besieging forces took advantage of their position to overrun the Zennyū and Tōzen temples and establish a base in the Dainichi Temple.
Understanding that a loss was inevitable, Nagafusa had his wife and three children, along with two retainers, flee to the protection of the Kyōkō Temple in her hometown. On the night of 7/15, he gathered surviving forces below the castle and, early the next morning, had them set fire to the area surrounding the main citadel, and then Nagafusa and his eldest son, Shinohara Nagashige, charged into the Dainichi Temple. While the army of Sogō Masayasu panicked, Nagashige approached the west entrance to the main encampment where Masayasu was located, but was struck down from behind by Uematsu Sukehisa, a retainer of the Kōzai clan. Nagafusa also died within the enemy camp. The battlefield extended over a broad area from the foothills of Uezakura Castle to the Dainichi Temple, with as many as 3,000 killed from both sides.
Nagafusa’s wife, his second son (Shinohara Shinjirō) and third son (Shinohara Yoshifusa) arrived without incident at the Kyōkō Temple. Thereafter, they escaped to Kii Province and later served as stewards of Toyotomi Hideyoshi. Shinjirō later returned to Awa and built a monument to his father and older brother.
This conflict served as a trigger for the band of retainers to separate from the Miyoshi family, engage in battles across Awa such as the Battle of Aratano, and instigate an invasion of Awa by Chōsokabe Motochika of Tosa Province.
After this battle, Uezakura Castle was abandoned and Kawashima Koretada, who made contributions in the battle, received a fief and built Kawashima Castle.