The Siege of Akechi Castle occurred from Tenshō 2 to Tenshō 3 (1574 to 1575) in the Ena District of Mino Province.  The battle was waged between the Takeda and Oda clans.

On 4/12 of 1573, Takeda Shingen (the shugo daimyō and sengoku daimyō of Kai Province and nineteenth head of the Takeda clan), died of illness en route to the capital of Kyōto.  Shingen was succeeded by his fourth son, Takeda Katsuyori.

Attacks by Takeda Katsuyori

On 1/27 of 1574, upon the last will of Shingen, Katsuyori led soldiers from Kai, Shinano, and three other provinces in a bid to contain Oda Nobunaga.  An army of 15,000 soldiers charged Akechi Castle which was in a vital location from which to attack Mino, Owari, Mikawa, and Tōtōmi provinces.  Tōyama Kazuyuki (the lord of Akechi Castle) and his uncle, Tōyama Tomoharu, commanded 500 men to defend the castle and sent an urgent message to Oda Nobunaga.  Nobunaga considered it to be a grave development to lose Akechi Castle, so he called upon his eldest son, Oda Nobutada, and senior retainer, Akechi Mitsuhide, to come from Tamonyama Castle in Nara to lead an army of 30,000 men. 

Under the first theory, the army set-up an encampment on Mount Tsuruoka to the northeast of Akechi Castle. Nobunaga then notified the defenders at Akechi of a plan to launch a pincer attack against the Takeda forces surrounding the castle.  On 2/5, Nobunaga and Nobutada deployed from Gifu Castle but, on 2/6, Iibama Uemon-no-jō (Takatō Tomonobu) launched a rebellion at Akechi Castle and eliminated Sakai Etchū-no-kami who had come with reinforcements to the castle.  Moreover, the spout from which to draw water near the rear gate was broken, so the citadels and area below the castle turned into a sea of fire, after which the castle fell to the Takeda.  Five hundred people died in the battle.  As a result, in eastern Mino, Nobunaga positioned Kawajri Hidetaka in Tsuruga Castle and Ikeda Tsuneoki in Ori Castle, and, on 2/24, withdrew to Gifu.

Under the second theory, out of eighteen castles under the Tōyama, Akechi Castle was the seventeenth to fall.  By the middle of the fourth month, the Takeda army toppled the Oda castles of Naegi, Atera, Ōi, Kushihara, Tsuruga and Tsumagi, along with Imami fortress, and laid siege to Akechi.  While defending to the last, Tōyama Tomoharu sought help from Nobunaga.  Nobunaga responded by deploying together with Nobutada.  While Nobunaga led an army of 30,000 men with commanders from Mino (the Ikeda, the Hachiya, Kawajiri Hidetaka, the Mori, and the Tsukamoto), Yamagata Masakage led 6,000 soldiers around the base of Mount Tsuruoka to block the route of the Oda forces, so Nobunaga pulled back and set-up a camp.  Consequently, Tōyama Tomoharu failed to receive reinforcements from the Oda army, so he died in battle and the castle fell.  Meanwhile, Tōyama Kazuyuki, the lord of the castle, and his uncle, Tōyama Toshikage, together fled the castle, and were sheltered by the Suzuki clan at Asuke Castle in Mikawa which was the family home of Toshikage’s wife.  Thereafter, the Takeda clan took advantage of an opportunity to dispatch a band from Kawanakajima to topple Iibama Castle.

In the fifth month of 1575, Nobunaga defeated Katsuyori at the Battle of Nagashino.  Next, Nobunaga’s eldest son, Oda Nobutada, served as the commander-in-chief to lead an army to subjugate the Takeda, recapturing numerous castles that were occupied by forces supporting the Takeda.  Tōyama Toshikage and Tōyama Kazuyuki toppled Ori Castle which was occupied by the Takeda army and then captured Akechi Castle for the Oda.  With the assistance of the Suzuki clan of Asuke Castle in Mikawa, Tōyama Toshikage and Kazuyuki returned to Akechi Castle.