Siege of Hachiman Castle

八幡城の合戦

Western Army

Mino Province

Eastern Army

Date:  9/1 to 9/4 of Keichō 5 (1600)

Location:  Hachiman Castle in the Gujō District of Mino Province

Synopsis:  During the prelude to the main Battle of Sekigahara, members of the Western Army attempted to defend Hachiman Castle from a three-pronged assault by the Eastern Army.  After a day of violent clashes, the besieging forces failed to topple the castle, but the defenders settled the following day.  Despite the settlement, Inaba forces arrived in support of the defenders to launch a surprise attack against the Endō army resulting in further casualties on both sides, after which the opponents settled again.  Siblings from the Endō clan fought on both sides of the conflict.

Commanders:  Inaba Sadamichi, Endō Tanenao

Forces:  Unknown

Casualties:  Unknown

Commanders:  Endō Yoshitaka, Kanamori Arishige

Forces:  Unknown

Casualties:  Unknown

The Siege of Hachiman Castle occurred from 9/1 to 9/4 of Keichō 5 (1600) at Hachiman Castle in the Gujō District of Mino Province.  This was one of the regional battles between the Eastern and Western armies in the prelude to the main Battle of Sekigahara on 9/15 of Keichō 5 (1600).  The battle was waged between forces led by Kanamori Arishige and Endō Yoshitaka for the Eastern Army and Inaba Sadamichi and Endō Tanenao for the Western Army.

After Toyotomi Hideyoshi died in the eighth month of 1598, the headship of the clan was inherited by his son and designated heir, Toyotomi Hideyori.  In the midst of the withdrawal of forces from the Korean Peninsula, a deepening divide occurred among leading members of the Toyotomi administration including a faction for civil administration led by Ishida Mitsunari and a military faction led by Katō Kiyomasa and Fukushima Masanori.  In the wake of Hideyoshi’s death, four magistrates including Mitsunari and Mōri Terumoto drafted a pledge reaffirming their support for Hideyori in the event any members of the Council of Five Elders held contrary opinions.  Meanwhile, from the tenth to the twelfth month of 1598, Tokugawa Ieyasu paid visits to assorted daimyō including Kyōgoku Takatsugu and Hosokawa Yūsai.  In addition, he covertly arranged for marriages with members of families affiliated with the military faction including Fukushima Masanori, Kuroda Nagamasa, and Hachisuka Iemasa.

In 1600, after Mitsunari raised arms against Ieyasu, Oda Hidenobu, the lord of Gifu Castle in Mino, Province aligned with Mitsunari for the Western Army and Inaba Sadamichi, the lord of Gujō-Hachiman Castle, entered Inuyama Castle in an effort to stop the westward advance of Ieyasu.  Endō Yoshitaka of the main branch of the Endō family in Kohara and Endō Tanenao of Shirakawa were together invited by Hidenobu and persuaded to join the Western Army.  Yoshitaka, however, had earlier been removed by Hideyoshi from his former position as the lord of Gujō-Hachiman Castle so, after consulting with his younger brother, Endō Yoshitane, decided to join the Eastern Army led by Ieyasu.  Nevertheless, Tanenao pledged to Hidenobu to join the Western Army and set-up at Uegane.  Yoshitaka then assigned his son, Endō Yoshikatsu, to guard the Myōkan Temple.

When Yoshitaka appealed to Ieyasu to reclaim Hachiman Castle, Ieyasu did not know that Tanenao had joined the Western Army.  On 7/29, notice arrived that Ieyasu granted Gujō to the Yoshitaka and Tanenao.  Yoshitaka established a position at Yoshida in the village of Sami to face-off against the forces at Uegane.  After receiving thirty arquebuses and ammunition from Hidenobu, Tanenao initiated an attack against Yoshitaka.  Meanwhile, after Kanamori Arishige (Yoshitaka’s son-in-law in Edo) followed orders from Ieyasu to quickly return to his base in Hida, Arishige advanced from the gateway to Sakamoto while a detached division marched from the gateway to Shirakawa and, on 9/1, informed Yoshitaka of a plan to mount an all-out assault against Hachiman Castle and urged him to converge with their forces.

At the time, Sadamichi was absent from Hachiman Castle and it was defended by his youngest son, Inaba Michitaka along with a small garrison.  To augment their defenses, Michitaka mobilized rōnin (wandering samurai), townspeople, and other adults from across the territory to harden their positions.  On 8/28, Yoshitaka led over 400 soldiers from Kohara, avoiding defenses set-up by the Inaba forces by traversing the Hida River to advance.  After defeating the Inaba defenses at Asagataki, Yoshitake divided his army into two battalions that arrived at Hoshimaru and Nojiri.  Yoshitaka’s younger brother, Yoshitane, attacked with over 400 soldiers from the gateway to Kutsube.  Around this time, Inaba Sadamichi was encouraged in a secret letter from an old acquaintance, Fukushima Masanori, to join the Eastern Army to which he complied.  Next, Masanori made a request via Itō Naomasa for Yoshitaka and Arishige to suspend their assault on Hachiman Castle but the response was that Yoshitaka had already deployed and Sadamichi was still at Inuyama so it was difficult to ascertain events there.  On 9/1, after departing from Hoshimaru, Yoshitaka’s army encountered an ambush on a ridge known as Naragatō, whereupon the forces reversed direction and set-up at Akatani.  One unit from this battalion burned down Nakano.

Reinforcements led by Kanamori Arishige went from the gateway to Sakamoto to Kusumi, changing course to avoid a clash with the Inaba forces and establishing a camp at Takiyama.  The detached division of the Kanamori army climbed Mount Gochō and, together with Yoshitaka’s forces at Akatani, prepared for a three-prong attack against Hachiman Castle.

On 9/1, the Endō army crossed the Yoshida River, breached fence barriers.  One battalion went toward a wooden entrance behind the castle while the main battalion under Yoshitaka headed toward the front gate.  Arishige’s army approached the rear gate but was thwarted by double moats while repeated clashes failed to yield a decisive victor.  During this time, Yoshitaka’s battalion approached the first entry to the front gate and, amidst arquebus fire from the defenders, forced their way into the castle.  Meanwhile, the detached battalion destroyed the unit defending the wooden entrance behind the castle and entered the outer citadel.  Arishige’s battalion charged but was blocked by the defenders, after which they broke-through the wooden entrance on the east side of the castle and entered the outer citadel.  As a result, the Endō and Kanamori armies briefly fought against one another in error, but soon combined their forces to initiate an attack from the second gate to the outer citadel.  At the rear gate, fighting persisted between the Kanamori and Inaba armies, resulting in numerous casualties.  At dusk, neither side had the upper hand so the besieging forces returned to their respective camps.

Following consultations between Yoshitaka and Arishige, a messenger was dispatched to the castle with a demand for surrender.  On 9/2, the opposing sides reached a settlement.  After Yoshitaka moved his main base to Mount Atago, a letter arrived from Ieyasu dated 8/21 recognizing Yoshitaka’s rights to the entire Gujō District.  Having learned of the emergency, Inaba Sadamichi headed from Inuyama toward Gujō.   His eldest son, Inaba Norimichi, along with Inaba Chūjirō (the lord of Nakayama Castle) followed him, arriving at Hachiman before dawn on 9/3.  That morning, the fog was thick and, immediately after the settlement, the Endō forces on Mount Atago let their guard down whereupon they were subject to a surprise attack by the Inaba forces.  Despite valiant fighting, Endō Yoshishige (Chōsuke), Sumi Yasuyoshi (Chūzaemon), Kayukawa Gorōzaemon, Kayukawa Kojūrō, and Etori Sakusuke were among those killed in action.  Yoshitaka was finally able to flee for safety to Arishige’s camp on Mount Ono.  Under a different account, Yoshitaka’s forces were not caught off-guard, and after the Inaba forces fired their arquebuses from the opposite shore and began to cross the river, Yoshitaka’s forces responded in kind with arquebus fire and many Inaba forces died in the river.  Ultimately, however, the attacking forces reached Mount Atago which led to a violent battle while Yoshitaka was spirited away by his retainers.  After significant casualties on both sides, the opponents returned to their bases at night.  Although Sadamichi entered Hachiman Castle, on 9/4, he sent a messenger out of the castle and the two sides reconciled again.

After Yoshitaka hurriedly returned his forces to eastern Mino, on 9/5, he attacked the fortress at Uegane and forced the surrender of Tanenao.  He sent a messenger to Tokugawa Hidetada in Shimosuwa in Shinano to inform him of the battle situation while Yoshitaka himself headed to meet Ieyasu.  A letter of commendation from Hidetada arrived and, on 9/14, Yoshitaka arrived at the main encampment of Ieyasu at Akasaka.  After providing an update on the battle situation to Ieyasu, he converged with the Eastern Army.  Meanwhile, following his surrender to Yoshitaka, Sadamichi retreated to Ise.  A servant named Katagiri Tomonori remained in the castle, but, after it became known across Gujō that Yoshitaka made a comeback, servants of the Inaba clan were subject to acts of violence and small skirmishes.  Retainers of the Inaba clan, however, tolerated these events in silence.

Following the victory by the Eastern Army at the Battle of Sekigahara, Inaba Sadamichi was transferred to Usuki in Bungo Province with a fief of 50,000 koku.  Early in the eleventh month, Yoshitaka took over Hachiman Castle and seized Nakayama Castle.  On 11/15, Yoshitane died and Yoshitaka gained possession of 27,000 koku across the Gujō District.