Battle of Kanegasaki
Date: Genki 1 (1570)
Location: From Kanegasaki in the Tsuruga District of Echizen Province via the Kutsuki Pass in Ōmi to the capital of Kyōto
Outcome: After a betrayal by Azai Nagamasa, Nobunaga faced the risk of a pincer attack, so he halted an invasion of Echizen to enable the allied Oda and Tokugawa forces to retreat to the capital under the protection of troops led by Kinoshita Hideyoshi in the rear guard.
The Battle of Kanegasaki occurred in Genki 1 (1570) as one of several clashes between Oda Nobunaga (a sengoku daimyō and head of the Oda family) and Asakura Yoshikage (a sengoku daimyō and eleventh head of the main branch of the Asakura). This battle is also referred to as the Kanegasaki-no-nokiguchi or Kanegasaki kuzure.
When Oda Nobunaga attacked Asakura Yoshikage in Echizen Province, he was betrayed by his ally, Azai Nagamasa, who favored close ties to the Asakura clan despite the political marriage between Nobunaga’s younger sister, Oichi-no-kata and Yoshikage’s son. The Azai were based at Odani Castle on the eastern shore of Lake Biwa. Confronting the risk of a pincer attack, Nobunaga drew upon Kinoshita Tōkichirō (later known as Toyotomi Hideyoshi) and the allied forces of Tokugawa Ieyasu to serve as the rear guard, while the main contingent of Oda forces provided coverage to withdraw to the Oda territory. The Battle of Kanegasaki arose from fighting in the course of this withdrawal.
The forces succeeded in attacking Kanegasaki Castle at the entrance to Tsuruga, but after receiving news of the alienation of the Azai, the Oda army began its retreat from this location, while the rear guard under Kinoshita Tōkichirō and battle to withdraw began from this same location.
Prelude to the battle
On 4/20 of 1570, a contingent of 30,000 allied forces of Oda Nobunaga and Tokugawa Ieyasu departed from the capital of Kyōto. In addition to commanders in the Oda army, bushō including Ikeda Katsumasa and Matsunaga Hisahide and nobles including Hino Terusuke and Asukai Masaatsu from the Kinki Region joined the army. The Genki era began on 4/23 at the time of this departure. Although this was an expedition to Echizen, the pretext for the deployment was an attack on Wakasa Province.
Course of events
In the invasion of the territory of Asakura Yoshikage in Echizen, the allied forces of the Oda and Tokugawa began on 4/25 by attacking the Asakura at Tezutsuyama Castle in the Tsuruga District. The following day, the forces defeated Asakura Kagetsune (the governor of the Tsuruga District and head of affairs of the family) at Kanegasaki Castle. The Asakura army then reinforced their positions around the Kinome Ridge with a topography suited to defending along a narrow front line, relinquishing the middle portion of the Tsuruga District. To complicate the situation for the Asakura, a power-struggle existed between Asakura Kagetsune and Asakura Yoshikage on one side and senior members of the clan including Asakura Kageakira and Asakura Kagetake on the other. These tensions may have caused a delay in the dispatch of reinforcements to Kagetsune.
Owing to these circumstances, the Oda enjoyed the upper hand in the conflict, but, then the news came of betrayal by Azai Nagamasa, his younger brother-in-law, based in northern Ōmi. Initially, Nobunaga considered the news to be a rumor, but as further information arrived, he had to acknowledge it as fact, and decided to withdraw because the allied Oda and Tokugawa forces confronted a risk of a pincer attack by the Asakura and Azai. The Oda may have ascertained the betrayal based on communications from Matsunaga Hisahide who became aware of suspicious movements among the Azai forces while Hisahide was engaged in diplomacy and reconnaissance in Ōmi and Wakasa provinces. There is also an unsubstantiated account that Nobunaga’s sister, Oichi-no-kata, informed him by slipping a note into a bag of adzuki beans tied with twine.
For the withdrawal, Nobunaga assigned Kinoshita Hideyoshi to Kanegasaki Castle. Hideyoshi may have offered to serve as the commander of the rear guard, but bushō of higher rank than Hideyoshi, including Ikeda Katsumasa (the military governor of Settsu) and Akechi Mitsuhide, were present, so Hideyoshi may not have been the commanding general. During Nobunaga’s retreat, his commanders exhibited extraordinary leadership, preventing any openings for the Asakura army to minimize losses.
With the assistance of Kutsuki Mototsuna, the head of an influential family in Ōmi, Nobunaga safely retreated with a small contingent of ten men from Tsuruga in Echizen over the Kutsuki Pass to the capital, arriving on 4/30. This was enabled in part by the efforts of Matsunaga Hisahide to convince Mototsuna to abandon an original plan to kill Nobunaga. Meanwhile, Ikeda Katsumasa led the main contingent of Oda forces to successfully return to Kyōto. Nobunaga conferred honors on Hideyoshi and provided him with gifts of gold.
While traversing the Kutsuki Pass, the rear guard led by Hideyoshi was assailed by a large group of robbers headed by a character named Sarutobi Jinsuke. Hideyoshi persuaded him to join his command and he made later contributions. On the day after arriving in the capital (on 5/1), Nobunaga inspected a palace under construction without a hint of the precarious escape. Thereafter, he returned to Gifu to reconstitute his forces in preparation for an expedition against Nagamasa.
The Oda army enjoyed success in the early stages of the conflict. There is a theory that Asakura Yoshikage may have been an adopted son from the Rokkaku clan. As a result, this may have caused a lack of consensus within the Asakura family, playing to the advantage of the Oda in the conflict. Under another theory, Ashikaga Yoshiaki, the shōgun, orchestrated the Battle of Kanegasaki aiming to rescue Takeda Motoaki who had been taken hostage and incarcerated by the Asakura.