Battle of Nakao Castle
Date: 11/21 of Tenbun 19 (1550)
Location: In the eastern environs of Kyōto on Mount Higashi in Yamashiro Province
Synopsis: After the loss of Miyoshi Masanaga and other key supporters, Hosokawa Harumoto (the deputy shōgun) became vulnerable to the army of Miyoshi Nagayoshi, so, along with Ashikaga Yoshiteru (the thirteenth shōgun), he fled Kyōto for the protection of the Rokkaku clan of southern Ōmi. Seeking to regain their authority, Yoshiteru and his father, Ashikaga Yoshiharu, built Nakao Castle as a base from which to challenge Nagayoshi’s army, but following aggressive countermeasures by Nagayoshi, were forced to flee again.
The Battle of Nakao Castle occurred on 11/21 of Tenbun 19 (1550) at Nakao Castle in the eastern environs of Kyōto on Mount Higashi.
Following the defeat of Miyoshi Masanaga and other supporters at the Battle of Eguchi in the sixth month of 1549, Hosokawa Harumoto (the deputy shōgun) initially withdrew to Kyōto. Fearing a pursuit, he then accompanied Ashikaga Yoshiteru (the thirteenth shōgun of the Muromachi bakufu) and Ashikaga Yoshiharu (Yoshiteru’s father and retired after serving as the twelfth shōgun) and together they fled the capital. With the assistance of Rokkaku Sadayori, the military governor of Ōmi Province, the contingent went to Sakamoto on the western shore of Lake Biwa. Meanwhile, in the seventh month, Miyoshi Nagayoshi (a former retainer of Harumoto who defeated him), marched to Kyōto and, in lieu of Yoshiteru who had fled, managed the affairs of the capital. Alarmed at these developments, Yoshiharu made plans to restore the authority of the Ashikaga shōgun family in Kyōto. On 0/18, he began construction of Nakao Castle on the backside of Mount Higashi in the environs to the east of the capital where the Jishō Temple was located. On 5/4 of Tenbun 19 (1550), Yoshiharu died of illness but his son, Yoshiteru, pledged to overthrow Nagayoshi and, on 6/9, he joined Harumoto to enter Nakao Castle. On 7/8, he deployed forces to Kitashirakawa, the Jōdo Temple, and Yoshida in the foothills of Mount Higashi.
On 7/14, a Miyoshi army of 18,000 soldiers led by Miyoshi Nagayasu, Miyoshi Nagatora (Nagayasu’s son), and Sogō Kazumasa marched to Kyōto, triggering a response from the bakufu army that led to fighting on the streets of the capital. However, the main force led by Harumoto remained in Yoshida while reinforcements from the Rokkaku army remained in Kitashirakawa without moving. Only 100 ashigaru, or lightly armed foot soldiers, went out to attack after which the small-scale clashes ended. This is known as the Battle of Higashiyama. At this time, when a noble named Yamashina Tokitsugu heard that one of Nagatora’s yoriki, or security officers, was shot and killed by arquebus fire, the record he made of this incident in his diary is the first known reference in Japan to the use of an arquebus in battle.
The clashes in the metropolis were small-scale, while the main forces from each side withdrew to Ōyamazaki and Nakao Castle respectively, so not much change was visible. On 10/20, the Miyoshi army marched to Kyōto again and clashed with the bakufu army on Mount Higashi, but this was also a limited engagement. In the eleventh month, Nagayoshi had his army attack aggressively, and, on 11/29, the forces set fire to the Shōgo Temple, Kitashirakawa, Shishigatani, and Tanaka to intimidate the enemy. At the same time, he arranged to send troops to Ōmi. On 11/20, he directed Matsunaga Nagayori toward Ōmi and troops set fire to the communities of Ōtsu and Matsumoto. Nagayoshi’s army marched to the environs of Lake Biwa so, fearing an attack from behind, Yoshiteru decided to withdraw. On 11/21, after setting fire to Nakao Castle, Yoshiteru’s forces fled first to Sakamoto, and then north to Katata. Two days later, on 11/23, the Miyoshi army entered Nakao Castle and it was destroyed.
Yoshiteru withdrew to Ōmi so, for a while, Nagayoshi was able to secure Kyōto. In the third month of 1551, however, he encountered two attempted assassinations followed by an attack on the capital by the bakufu army, forcing him into another defensive battle.