Battle of Fubeyama

布部山の戦い

Amago Clan

Izumo Province

Mōri Clan

Date:  2/14 of Eiroku 13 (1570)

Location:  On and around the foothills of Mount Fube in Izumo Province

Synopsis:  Yamanaka Yukimori, the lead commander of the Amago revival army, established positions on Mount Fube in a last stand effort to prevent the Mōri army from marching north in support of the garrison under siege by the Amago at Gassantoda Castle.  In the early stages, the Amago benefited from their elevated position to slow the advance of the Mōri soldiers, but after their hilltop encampment was overrun, the tide quickly turned against them, causing the Amago to flee with the Mōri in pursuit.

Lord:  Amago Katsuhisa

Commanders:  Yamanaka Yukimori, Tachihara Hisatsuna, Moriwaki Hisanori

Forces:  6,000 to 7,000

Losses:  200 to 300 soldiers

Lord:  Mōri Motonari

Commanders:  Mōri Terumoto, Kikkawa Motoharu, Kobayakawa Takakage

Forces:  13,000 to 89,000 (varies by historical account)

Losses:  112 soldiers

Yamanaka Yukimori

Mōri Terumoto

The Battle of Fubeyama occurred on 2/14 of Eiroku 13 (1570) as a pivotal clash between the Amago army seeking to revive the Amago clan and the Mōri army aiming to halt a resurgence of the Amago clan.  This is referred to as the Battle of Fubeyama owing to the location of the battle in Nakayama in Fube, approximately twelve kilometers south of Gassantoda Castle in Izumo Province.

Background to the conflict

Decimation of the Amago clan

On 7/3 of Eiroku 5 (1562), Mōri Motonari, the head of the Mōri clan, marched toward Izumo Province for the purpose of eliminating the Amago clan.  After entering Izumo, the Mōri army led by Motonari advanced by compelling the surrender one after another of influential kokujin, or provincial landowners, aligned with the Amago.  In the twelfth month of 1562, the Mōri established a main base at Arawai Castle on the Shimane Peninsula and commenced attacks on Gassantoda Castle, the base of the Amago clan.

In response to the invasion by the Mōri army, the Amago forces vigorously fought back across the province.  However, in the tenth month of 1563, the Mōri captured Shiraga Castle situated on the Shimane Peninsula in a key location for the provision of supplies.  This is known as the Siege of Shiraga Castle.  Next, by early in 1565, the Mōri took control of all of western Hōki Province, leaving the Amago base at Gassantoda Castle completely isolated.

In addition to severing the supply routes of the Amago, in the fourth month of 1565, the Mōri moved their main base from Awarai to Hoshikamiyama and then commenced attacks against the Amago at Gassantoda Castle.  Below the castle, the Mōri army destroyed the croplands and, on 4/17, launched an all-out attack on the castle in an event known as the Second Siege of Gassantoda Castle.  Owing to the valiant defense of the Amago, this effort ended in failure, but, later, the Mōri army switched to a strategy to cut-off their supplies, increasing pressure on the defenders in the castle.

On 11/21 of 1567, Amago Yoshihisa, a daimyō and the head of the Amago family under siege by the Mōri at Gassantoda, determined that he could not continue to resist and thereby surrendered to the Mōri.   On 11/28, Yoshihisa vacated the castle and the Amago clan as a sengoku daimyō family was temporarily extinguished.  Their base at Gassantoda Castle, along with the territory of the Amago, can under the control of the Mōri.  Yoshihisa, along with three siblings and some of his retainers were taken to the Enmyō Temple and incarcerated.  Other retainers of the Amago were ousted from Izumo and became rōnin, or wandering samurai.

Invasion by the Mōri of Kyūshū and invasion by the Amago revival army of Izumo Province

After eliminating the Amago clan and taking control of nearly all of the Chūgoku Region, the next objective of the Mōri was the conquest of the Ōtomo clan in northern Kyūshū.  In 1568, Motonari ordered the return to Aki Province of forces led by Kikkawa Motoharu (Motonari’s second son) and Kobayakawa Takakage (Motonari’s third son) after their deployment to Iyo Province in a campaign known as the Deployment of the Mōri to Iyo.  In the eighth month of 1568, Motonari dispatched these two commanders to northern Kyūshū to commence the conquest of the Ōtomo clan.  In the fourth month of 1569, Motonari departed from his base at Yoshida-Kōriyama Castle and headed for a deployment in Nagato Province.  In the fifth month, after entering Chōfu, he established a main base for the conquest of the Ōtomo, leading into the Battle of Tatarahama against Ōtomo Yoshishige (Sōrin) over control of Tachibanayama Castle.  In conjunction with Motonari’s deployment, he ordered the deployment to Kyūshū of numerous kokujin, or provincial landowners, from the Sanin Region so that the Mōri territory in that region was not well-protected.

Meanwhile, despite the decimation of the Amago clan, some of their former retainers who had become rōnin aimed to revive the family.  The ringleader of these individuals was Yamanaka Yukimori.  In 1568, after wandering around the provinces, Yukimori arrived in Kyōto, whereupon he persuaded Amago Katsuhisa (the orphan of Amago Sanehisa – a member of the Amago family) to leave the Tōfuku Temple were he was serving as a monk and backed him as a general of the Amago revival army.  Yukimori then called upon former retainers of the Amago from throughout the region to come together to secretly plan a war to revive the clan.  Yukimori was one of ten elite soldiers referred to after the Sengoku period as the Amago jūyūshi, or the Ten Warriors of the Amago.  These soldiers served in a coordinated effort to restore the Amago clan to power in Izumo after losing the province in 1566 following an invasion by Mōri Motonari.

On 6/23 of Eiroku 12 (1569), the Mōri sent an army to northern Kyūshū to attack the Ōtomo.  Having waited for an opportune time to strike, Yukimori chose this time to have the Amago revival army commence an invasion Izumo Province.  Departing from Tajima Province, the Amago revival army sailed in several hundred boats to land on the Shimane Peninsula whereby they occupied the nearby Chūyama fortress.  After Katsuhisa and the Amago revival army shouted their war cry for revival, former retainers residing underground in the province came together, and, within five days, the contingent grew to over 3,000 men.  At the end of the month, Yukimori and the revival army attacked Shinyama Castle defended by Taga Genryū.  Next, the forces constructed Suetsugu Castle on the northern shore of Lake Shinji to serve as their base of operations.  Then, the revival army expanded its influence by engaging in battles across the Sanin Region.  This is known as the Invasion of Unshū by the Amago revival army.

Withdrawal of the Mōri from Kyūshū

On 5/3 of 1569, after their battle against the Ōtomo, the Mōri captured Tachibana Castle but the Ōtomo army continued to stay at the site so the Mōri soldiers could not redeploy.  Around this period is when the position of the Mōri clan became precarious.

Toward the end of the seventh month, as noted in a letter by Amano Takashige (the lord of Gassantoda Castle) the rōnin (meaning the members of the Amago revival army) had support from persons all over Izumo Province, enabling them to reassert control.  On 10/11, Ōuchi Teruhiro, with the support of the Ōtomo clan, crossed the ocean and, on the following day, attacked the remains of the Ōuchi resident in Suō Province, temporarily occupying the location.  This event is known as the Revolt of Ōuchi Teruhiro.  This suddenly led to the most significant crisis confronting the Mōri with respect to their governance of the provinces in the region.

Owing to these developments, Mōri Motonari, as the head of the Mōri clan, decided to withdraw his army from northern Kyūshū.  On 10/15, after leaving behind Nomi Munekatsu, Katsura Motoshige, and Saka Motosuke, and a small number of troops, the Mōri army commenced its withdrawal, while other units of the Mōri army stationed in Kyūshū joined the withdrawal as permitted.  On 11/21, Nomi Munekatsu also withdrew from the castle and, with the exception of Moji Castle, made a full withdrawal from northern Kyūshū.

Course of events

Invasion by the Mōri army of Izumo Province

On 10/18 of Eiroku 12 (1569), after the Mōri army under the command of Kikkakwa Motoharu and Kobayakawa Takakage arrived in Chōfu from Kyūshū, around 10/25, these forces suppressed the revolt by the Ōuchi revival army.  Teruhiro killed himself in Tonomi and the war by the Ōuchi revival army ended after just a few weeks.  After subduing the rebellion, on 12/23, the Mōri army evacuated Chōfu and returned to their base in Yoshida-Kōriyama Castle.

On 1/6 of 1570, after a brief respite in their home province, Mōri Terumoto, Kikkawa Motoharu, and Kobayakawa Takakage deployed with their forces from Yoshida-Kōriyama Castle to subdue the Amago revival army.  In all, the contingent had approximately 26,000 soldiers.  Serving as the commander-in-chief, Terumoto led a division of 6,000 hereditary retainers of the Mōri while Motoharu led the Iwami forces, Takakage led the Bingo forces, and Shishido Takaie led the Bitchū forces.  These forces were accompanied by a navy of 200 vessels.  As a first priority, the Mōri army aimed to come to the rescue of those at Gassantoda Castle who were under siege by the Amago revival army.  Around this time, the Amago forces were attacking the castle, while the Maki, the Kōmoto, and the Yubara clans surrendered, presenting a dangerous situation.  Moreover, supplies had dwindled in the castle so the Mōri needed to quickly break the siege by the Amago forces and supply military provisions to the castle garrison.

First, the Mōri had Kodama Narihisa lead a flotilla of 200 vessels from the Seto Inland Sea to Yunotsu in Iwami Province.  At this location, the forces summoned kokujin aligned with the Mōri and, to place in check the Amago revival army, sent them toward the Kitsuki Inlet (Inasa Beach) in Izumo.  Next, the main division led by Terumoto traveled by road toward Gassantoda Castle, and then headed north to Yamanami in Iwami to gather troops together and increase the strength of their forces.  The Mōri army then proceeded northwest, crossing the border into Izumo and, on 1/16, arriving in Akana.  The Mōri army was received by Akana Hisakiyo (also known under the name of Morikiyo), the lord of Akana Castle, and then changed direction to march north.  On 1/28, the contingent traversed Naka, and then, on 2/7, advanced to Misawa and Yokota.  In this manner, the Mōri army steadily progressed toward Gassantoda Castle and, along the route, were attacked by forces from outlying castles on the side of the Amago.

Attack by the Amago revival army

Meanwhile, the Amago revival army spent time and resources contending with the Battle of Harate and a subsequent revolt by Oki Tamekiyo in the Battle of Mihonoseki.  These clashes prevented the Amago forces from attacking the base of the Mōri in Izumo at Gassantoda Castle.  On 1/28, the Mōri army attacked Takuwa Castle defended by Takuwa Yamato-no-kami.  The Amago could not muster reinforcements to help them so the castle fell in just one day.  The Amago revival army could not stop the invasion by the Mōri much less buy time.  Yukimori and the Amago revival army chose Nakayama in Fube as the location to make a last stand against the attacks by the Mōri whereupon the scattered forces converged upon the site and prepared for a final showdown.

Nakayama in Fube (Fubeyama) was situated twelve kilometers south of Gassantoda Castle.  This was a critical location that must be traversed when going from Mitoya through Misawa and Yokota to Gassantoda Castle.  Furthermore, the road from this area to Gassantoda Castle traveled along the ridgeline of Mount Fube and it was necessary to climb once from the foothills to the top of the mountain.  The environs were surrounded by steep mountains so, to climb to the road on the ridgeline required going through one of two passages, either Mizutaniguchi on the west side or Nakayamaguchi on the east side.  In other words, to proceed from the direction of Misawa and Yokota to Gassantoda Castle, travelers had to pass through either Mizutaniguchi or Nakayamaguchi to the valley so, by controlling these two access points, the Amago had an opportunity to halt the march of the Mōri army.

The fall of Yōgaiyama Castle and arrival of the Mōri army

Yamanaka Yukimori and Tachihara Hisatsuna deployed after leaving the head of the Amago revival army, Amago Katsuhisa, in Suetsugu Castle with a small number of soldiers.  Their plan was to give the appearance that a large contingent remained in the castle to buy time needed to gather allied forces while raising doubts among the Mōri whether the scheme of the Amago was to deploy with a small number of forces.  Yukimori then summoned forces from various locations and, on 2/11, succeeded in setting-up a base on Mount Fube before the Mōri could attack.  The next day, the Mōri army advanced to Hida located twelve kilometers south of Mount Fube.  Yukimori divided his army into two equal battalions, positioning them halfway up the mountain in Mizutaniguchi and Nakayakaguchi.  The main base was established near the top of Mount Fube.

On 2/7, the Mōri army based at Misawa and Yokota left forces to secure Kakeya and Umaki.  On 2/12, the army passed through Hida and, on 2/13, advanced to Fube.  That same day, the forces attacked Yōgaiyama Castle in Fube defended by members of the Amago revival army.  Moriwaki Hisanori served as the commander of a garrison of 300 soldiers defending the castle.  Owing to the relatively small size of his garrison and the small size of the castle itself, Hisanori convinced Yukimori to abandon the site before an imminent attack by the Mōri.  After the capture of Yōgaiyama Castle, the Mōri army learned that the Amago revival army had divided into two battalions on Mount Fube so Terumoto established a position to the rear.

The Battle of Fubeyama

Around 7:00 AM on 2/14, the Mōri army commenced attacks against the Amago revival army based at Fubeyama.  The battle began in favor of the Amago revival army who benefited from their location above their enemy.  As the Mōri forces attempted to attack uphill from their positions in the foothills of the mountain, the Amago forces rained down fire from arquebuses and shot arrows at them, killing many below.  At Mizutaniguchi, an Amago unit led by Moriwaki Hisanori killed Hososako Sakyō-no-suke, the designated heir of Kumagai Nobunao (a commander in the Mōri army), while at Nakayamaguchi, Yokomichi Norimasa and Yokomichi Gensuke (brothers serving as commanders in the Amago army) killed Tamon Uemon-no-jō and Awaya Matazaemon (commanders in the Mōri army) so that, despite their inferior numbers, the Amago army gained the upper hand against the Mōri.

Nevertheless, Kikkawa Motoharu of the Mōri army learned of a sideroad owned by a local wealthy family that went to the top of Mount Fube.  He then led a detached unit up this road to the top of the mountain.  After launching a surprise attack against the main base of the Amago army, the situation changed dramatically.  After hearing that their main base had fallen, the Amago troops lost their footing and, in the face of enduring attacks by the Mōri, the Amago revival army disintegrated.  In this way, the tides of battle turned in favor of the Mōri while the remaining members of the Amago army fled in defeat.  As the Mōri forces continued to pursue them, many, such as Yokomichi Hidetsuna and Meguro Sakonemon, were killed in flight.  Serving as the rear guard for the Amago, Yamanaka Yukimori and Tachihara Hisatsuna were able to safely return to the base of the Amago at Suetsugu Castle.

Aftermath

After prevailing in this battle, on 2/15, the Mōri army succeeded in liberating Gassantoda Castle from the siege by the Amago revival army and supplying provisions.  By this time, there were no provisions remaining, and the defenders faced precarious circumstances.  Terumoto and the Mōri army conferred honors upon the soldiers of the garrison and then reconstituted the army.  Around the end of the month, a contingent of approximately 7,000 soldiers departed with the aim of attacking the Amago revival army at their base at Suetsugu Castle.  Suetsugu Castle was located on the plains and not suited for holding out against attackers so the Amago revival army decided to abandon the site and withdraw to Shinyama Castle.

Thereafter, fighting between the Mōri army and the Amago revival army spread across the Sanin Region.  At his base in Yoshida-Kōriyama Castle, Mōri Motonari experienced  deteriorating health.  After the Mōri army returned to its base with only Motoharu’s forces remaining in the field, the Amago revival army temporarily achieved a resurgence, but, before long, Motonari dispatched the navy division under his direct command.  These additional forces enabled the Mōri to gradually overwhelm the Amago forces.  Around 8/20 of 1571, approximately one and one-half years after the start of fighting, the last base of the Amago at Shinyama Castle fell to an attack by the Mōri.  Amago Katsuhisa fled from the castle to Oki Province, marking the end to the presence of the Amago revival army in Izumo.

Anecdotes

With respect to the fortress in Takuwa built by the Amago, the army stationed 500 troops under the command of Akiage Munenobu, Fukuyama Jirōzaemon, Endō Jinkurō, and Kawasoe Umanosuke.  Upon the approach of a Mōri army with as many as 20,000 mounted soldiers, instead of fighting, Munenobu burned down the fortress and fled.  During the escape, a total of 177 Amago forces were killed by the pursuing army.  Meanwhile, the Mōri incurred a loss of 23 soldiers including Murakami Matazaemon.  Under another theory, the fortress was protected by Akiyake Orinosuke and Mottomo Dōrinosuke (commanders in the Amago revival army), and, similar to the other story, upon the approach of the Mōri army, burned down the fortress and fled.

Yamanaka Yukimori had numerous empty encampments built on the peaks and in the valleys of Fube, giving the appearance that an army of 10,000 mounted soldiers were in these locations.  In an effort to prevent the enemy from learning of this scheme, he identified three colluders and had them decapitated.  However, in the preceding year, Kikkawa Motoharu of the Mōri army had sent bribes to rebels throughout the area of Tomita to persuade them to become allies.  Many were engaged in collusion so the plan was uncovered.

As the battle began, while Mōri Terumoto, the commander-in-chief of the Mōri forces was sitting on his folding stool, a huge bolder that even thirty men could not move came thundering down the mountain behind him.  This did not startle Terumoto who, instead, said that heaven was combining its power with him to defeat the enemy, or else sending a signal to everyone to hasten the battle.  This reaction emboldened his men.

Kikkawa Motoharu and Kobayakawa Takakage of the Mōri army dispatched a reconnaissance unit of 80 mounted soldiers to assess the encampment of the Amago.  In a bid to stop the party, Yamanaka Yukimori led about 100 mounted soldiers toward them and, without fighting, withdrew.  During the withdrawal, a single mounted soldier from the Mōri named Endō Gorōsanrō Motosada ran back and attempted to challenge Yukimori with his spear.  Yukimori fended-off the spear and, in return, stabbed the eye of his opponents horse with his own spear.  This caused the horse to plunge into the valley, while Motosada was stopped from falling by a thicket.  Yukimori told Motosade that he was brave to challenge him with a spear, so this time he was saved by the grace of heaven.  Before leaving, Yukimori told him to fulfill his destiny as a soldier by quickly getting up and returning to his camp.

When Yamanaka Yukimori himself planned to charge the enemy army, Teramoto Seishisuke, said that the commander-in-chief should not engage in such frivolous acts, and that he wanted to fight the enemy so, with Yukimori’s permission, he wanted to borrow Yukimori’s helmet with the dear horn crest.  At first, Yukimori disagreed, but, through the mediation of those around him, calmed down and allowed Seishisuke to wear the helmet.  Seishisuke then led a unit of 30 mounted soldiers on a charge into the enemy forces, whereby Seishisuke killed two enemy troops including Kodama Yashichirō Narishige and Tamon Uemon-no-jō Narimasa.  Seishisuke was also counted as one of the Ten Warriors of the Amago, an elite group of soldiers revered after the Sengoku period.

Yokomichi Hyōgo-no-suke (Hidetsuna) of the Amago revival army rested on the side of the road after incurring injuries when Nakai Zenzaemon approached.  Given that Zenzaemon was the husband of his niece, Hyōgo-no-suke let down his guard and noted that he had been injured, whereupon Zenzaemon, without responding, speared him and took his head.  Just ten days earlier, Zenzaemon had surrendered to the Mōri, making the Amago forces his enemy.  Owing to his familiarity with Zenzaemon, Hyōgo-no-suke became careless and was killed. Friends and foes alike said that Zenzaemon’s actions were those of a beast with a human face but did not resent him.

Meguro Sakonemon of the Amago revival army incurred injuries, making it difficult to retreat, so he requested a local landowner who was on friendly terms to allow him to shelter in a residence.  The owner consented, assisting Sakonemon to hide inside a chest, but Sakonemon was being pursued, so Mōri soldiers entered the dwelling.  Concluding that there was no escape, he felt it would be regrettable to be killed by the enemy soldiers so he crawled out of the chest and committed seppuku instead.

Yamanaka Yukimori of the Amago revival army had silver tassets on his suit of armor that were conspicuous during his retreat.  Kosaka Etchū-no-kami pursued him to within one ri, or approximately 4 kilometers, but Yukimori was swift of feet, enabling his escape.