Battle of Ajiki
Date: 7/18 of Tenbun 23 (1554)
Location: The village of Ajiki in the Kasugai District of Owari Province
Outcome: Shibata Katsuie, a senior retainer of Oda Nobukatsu (known as Nobuyuki), fighting on behalf of the Shobata-Oda sub-branch, benefited from the use of longer spears to defeat forces fighting for the Kiyosu-Oda branch.
The Battle of Ajiki occurred on 7/18 of Tenbun 23 (1554) in Ajiki in Owari Province. It is also referred to as the Battle of Nakaichiba.
Course of events
In this era, the Shiba clan served as the military governors of Owari Province, with Shiba Yoshimune serving as a shugo daimyō and the fourteenth head of the clan.
Under the Shiba, the Oda clan was divided into two branches, the Iwakura-Oda (Ise-no-kami) family governing the upper four districts of Owari and the Kiyosu-Oda (Yamato-no-kami) family governing the lower four districts. The Iwakura-Oda were the lineal heirs to the Oda clan and therefore regarded to be in a superior position vis-à-vis the Kiyosu-Oda. The Kiyosu-Oda family was supported by three sub-branches, referred to as the Kiyosu sanbugyō, or three magistrates. These branches included the Inaba-no-kami family, the Tōzaemon family, and the Danjō-no-jō family. The Danjō-no-jō is also referred to as the Shobata-Oda clan. Oda Nobutomo served as the deputy military governor of the Kiyosu-Oda family while Sakai Taizen served as his vice-deputy.
As the head of the Oda Danjō-no-jō sub-branch, Oda Nobuhide competed against these retainers to become the most influential figure in the Kiyosu-Oda clan (Yamato-no-kami family) governing the four lower districts of Owari. Nobuhide expanded his influence to become a sengoku daimyō. Following Nobuhide’s death on 3/3 of 1552, he was succeeded by his son, Oda Nobunaga, while Sakai Taizen continued to wield power under the deputy military governor of the Kiyosu-Oda family, Oda Nobutomo. Taizen proceeded to conspire with fellow clan members including Sakai Jinsuke, Kawajiri Yoichi (Sama-no-jō) and Oda Sanmi to oppose Nobunaga. However, on 8/16 of 1552, he lost at the Battle of Kayazu and Jinsuke was killed.
At Kiyosu Castle in Owari, Shiba Yoshimune (the military governor) had become the puppet administration of Nobutomo (the deputy military governor). In turn, Nobutomo’s authority was challenged by the Sakai and Kawajiri clans who were his retainers. Close retainers of Yoshimune, including Yanada Yajiemon and Nagoya Yagorō, colluded with Nobunaga, whereupon Nobunaga directed his troops to Kiyosu and had them burn the town surrounding the castle. Nobunaga himself joined the mounted soldiers, but owing to the robust defense of the castle, withdrew. In an effort to oust Nobunaga, Nobutomo endeavored to ally with the Imagawa clan, a long-time rival of the Shiba, despite opposition from Yoshimune.
On 7/12 of 1554, while Shiba Yoshikane (the son of Yoshimune) and other senior members of the family were out fishing, Sakai Taizen, along with Kawajiri Saemon and Oda Sanmi, took advantage of weak defenses at the castle to launch a surprise attack against Yoshimune, killing him and twenty or more members of the family. Yoshikane then fled to Nagoya Castle under the protection of Nobunaga.
On 7/18, Shibata Katsuie deployed to Kiyosu and fighting broke out on the route to enter Sanō. After attempting to fight back in front of the Seigan Temple, the retreating forces from Kiyosu could not hold on to the village of Ajiki in the Kasugai District, and were pushed back to the trenches near the entrance to the village. Kawajiri Sama-no-jō and Oda Sanmi fought valiantly, but the Shibata forces wielded longer spears than the Kiyosu forces, resulting in the battlefield deaths of Sama-no-jō, Sanmi, and thirty mounted soldiers. Sanmi was killed by a direct retainer of Yoshimune named Yū Kiichi.
Although Shibata Katsuie later became one of Nobunaga’s most senior commanders, at this time he was a senior retainer of Oda Nobukatsu (the lord of Suemori Castle also known as Nobuyuki), the younger brother of Nobunaga who was out of favor with Nobunaga. Under one theory, Katsuie increased his forces owing to the possibility that Nobunaga would seize leadership of the clan in a battle to avenge the deaths of fellow combatants.