Battle of Hetsugigawa
Date: 12/12 of Tenshō 14 (1586)
Location: Alongside the Hetsugi River in Bungo Province in northeast Kyūshū
Synopsis: Following a strategy meeting, Sengoku Hidehisa made a fateful decision to traverse the Hetsugi River and attack the Shimazu instead of waiting for additional forces to arrive. The attack failed, resulting in a significant loss for the Toyotomi. Hidehisa survived the battle but over 1,000 died and his domain in Sanuki Province was seized upon orders of Toyotomi Hideyoshi.
Commanders: Sengoku Hidehisa, Chōsokabe Motochika, Chōsokabe Nobuchika, Ōtomo Yoshimune, Sogō Masayasu, Yorioka Sakyōshin
Forces: 20,000 (able to place in action up to 6,000)
Casualties: Over 1,000 including Chōsokabe Nobuchika and Sogō Masayasu
The Battle of Hetsugigawa occurred on 12/12 of Tenshō 14 (1586), marking the opening chapter in Toyotomi Hideyoshi’s campaign known as the Kyūshū Pacification (Kyūshū heitei). In this conflict, Shimazu Iehisa led the Shimazu forces to victory against a Toyotomi army led by Chōsokabe Motochika, Chōsokabe Nobuchika, Sengoku Hidemasa, Ōtomo Yoshimune, and Sogō Masayasu.
On 4/5 of 1586, Ōtomo Yoshishige, the sengoku daimyō of Bungo Province met with Toyotomi Hideyoshi in Ōsaka. Yoshishige requested support to counter an advance by Shimazu Yoshihisa into Bungo. Hideyoshi consented, ordering Kuroda Yoshitaka to assemble Mōri forces for deployment to Kyūshū. He further ordered Sengoku Hidehisa from Sanuki Province to lead forces from Shikoku including Chōsokabe Motochika and his son, Nobuchika, to Bungo in Kyūshū.
Course of events
Shimazu Iehisa invaded Bungo, attacking Tsuruga Castle held by the Ōtomo. On 12/11, in support of the defenders, Sengoku Hidehisa and Chōsokabe Nobuchika set-up an encampment alongside the Hetsugi River. At a strategy meeting, Hidehisa insisted the forces should cross the river and attack, while Motochika advised the army wait for additional forces to arrive before commencing an attack. Hidehisa refused Motochika’s recommendation, while Sogō Masayasu concurred with Hidehisa. Consequently, the forces quickly crossed the river to engage in battle from the evening of 12/12 and continuing into the next day. Hidehisa’s unit serving in the vanguard was taken by surprise and promptly defeated. A battalion of 3,000 forces under Chōsokabe fought against an army of 5,000 soldiers under Niiro Daizen-no-suke. In the ensuing chaos, Motochika and Nobuchika became separated while on the defensive. Motochika managed to escape safely to Hiburijima, a small island off the coast of Iyo Province. Nobuchika sought refuge in Nakatsuru-Kawahara, but was killed by Suzuki Daizen. He died at the age of twenty-two. Sogō Masayasu and as many as 700 soldiers under Nobuchika also perished, while Tsuruga Castle fell. Hideyoshi was dismayed at the loss by Hidehisa, seizing his territory in Sanuki and assigning it to Bitō Tomonobu.