Battle of Shiritarezaka

尻垂坂の戦い

Uesugi Clan

Etchū Province

Ikkō-ikki

Date:  Early in the ninth month of Genki 3 (1572)

Location:  Shiritarezaka in Etchū Province

Outcome:  After the failure of earlier incursions by Uesugi forces in Etchū, Uesugi Kenshin led a large army on a successful invasion of Etchū against signficant numbers of Ikkō-ikki forces from Kaga and Etchū.

Commanders:  Uesugi Kenshin, Kawada Nagachika, Yamaura Kagekuni, Sanponji Sadanaga, Ajisaka Nagazane

Forces:  10,000 to 20,000

Casualties:  Few in number

Commanders:  Sugiura Gentō, Akihide (Zuisen Temple), Kenei (Shōkō Temple), Suiina Yasutane, Jinbō Nagashiro

Forces:  20,000 to 30,000

Casualties:  Over 4,000 (assorted theories)

The Battle of Shiritarezaka occurred early in the ninth month of Genki 3 (1572) at Shiritarezaka in Etchū Province.  In this conflict, Uesugi Kenshin defeated the combined forces of the Kaga Ikkō-ikki and the Etchū Ikkō-ikki.  This is also known as the Battle of Toyama Castle.

The Ikkō-ikki of the Hokuriku region including in Kaga and Etchū possessed a large quantity of arquebuses similar to members of the Ishiyama-Hongan Temple who fought against Oda Nobunaga; moreover, the Ikkō-ikki were all adherents of the Jōdo sect of Buddhism so had a firm sense of solidarity.  For Kenshin, the Ikkō-ikki posed a formidable enemy second only to Takeda Shingen and Hōjō Ujiyasu.  Based on victories by Kenshin at the Battle of Shiritarezaka as well as conflicts before and after this event, he had a definitive advantage over the forces including the Ikki who opposed him in Etchū.  After validating his leadership, he pacified Etchū and opened a path to march upon the capital of Kyōto.

Confrontation between Uesugi Kenshin and the Etchū Ikkō-ikki

Similar to the Ikkō-ikki in other provinces in the Hokuriku region such as in Kaga and Echizen, the Etchū Ikkō-ikki had historically wielded strong influence.  The father of Uesugi Kenshin (Nagao Tamekage) and grandfather (Nagao Yoshikage) of Echigo engaged in fierce ongoing conflicts against the Etchū Ikkō-ikki.  As the deputy military governor of Echigo, Kenshin inherited the family and, even after becoming lord of Echigo, continued to conflict with the Etchū Ikkō-ikki.  Kenshin was also opposed in northern Shinano and Kawanakajima by Takeda Shingen of Kai.  To contain Kenshin from behind, Shingen instigated actions by the Kaga Ikkō-ikki and the Etchū Ikkō-ikki.

On 8/23 of 1556, one of Kenshin’s retainers, Ōkuma Tomohide of Mikaburi Castle in Echigo, colluded with Shingen to rebel and led ikki forces from Etchū to attack Echigo.  Kenshin dispatched Ueno Ienari and defeated them in an event known as the Battle of Komagaeri.

On 3/29 of 1560, Kenshin attacked Jinbō Nagamoto (a daimyō and the deputy military governor of Etchū who joined with ikki forces to expand his power) at his base at Toyama Castle and achieved a victory.  However, Kenshin deployed to Kantō and, while battling against Hōjō Ujiyasu of Sagami, Nagamoto rose-up again to attack.  In the ninth month of 1562, Kenshin attacked Nagamoto at Masuyama Castle and forced him to surrender.

In 1568, Kenshin invaded Etchū in a bid to support Toyama Yoshitsuna to reacquire his position as the military governor of Noto following a rebellion by a band of retainers against Yoshitsuna in the prior year.  While confronting the ikki forces in Hōjōzu, on 3/16, Kenshin initiated an attack against Moriyama Castle in an event known as the Battle of Hōjōzu.  In response, the head of the Etchū Ikkō-ikki named Kenei of the Shōkō Temple (the Anyōji gobō, or monk’s quarters) informed the head of the Kaga Ikkō-ikki named Tsubosaka Kaneaki (Tsubosaka Hōki-no-kami) of the Kanazawa gobō, of Kenshin’s invasion of Etchū and warned him to be vigilant.  On 3/25, news arrived that one of Kenshin’s retainers, Honjō Shigenaga of the Agakita group, had started a rebellion in Echigo (an event known as the Honjō Shigenaga Conflict) whereupon Kenshin suspended the attacks in Etchū.  As Kenshin retreated to Echigo to suppress the rebellion, Kenei launched a counterattack against the flank of Kenshin’s army.  Meanwhile, Kenei’s son, Kenkō followed his father by fighting against Kenshin for years, in addition to joining members of the Ishiyama-Hongan Temple in their defense of Ōsaka Castle against Oda Nonunaga at the Battle of Ishiyama.

In 1569, after having suppressed the rebellion by Honjō Shigenaga, Kenshin led a large army to attack Matsukura Castle over a period of one hundred days where Shiina Yasutane, the deputy military governor of Etchū, was holed up after having joined with the Ikkō-ikki to rebel in the prior year.  This was the first attempt by the Uesugi to capture the stronghold known as the Siege of Matsukura Castle.  However, as one of three major mountain fortresses in Etchū, Matsukura was impregnable to attack, and, in addition to the unsettled situation in the Kantō, the Uesugi forces could not capture the castle.

During the second and third months of 1571, Kenshin deployed to Etchū with an army of 28,000 soldiers.  And, after several years of stiff resistance, overcame the defenders to topple the castle.  Thereafter, the Uesugi army defeated enemies at numerous other castles in Etchū including Toyama Castle, Shinjō Castle, and Moriyama Castle.  The Uesugi forces rode this momentum to advance from the east to the central portion, and then to the western portions of Etchū, overwhelming Shiina Yasutane and ikki forces.

Convergence of the Etchū Ikkō-ikki and the Kaga Ikkō-ikki

On 4/28 of 1571, Takeda Katsuyori, the successor to Takeda Shingen, sent a letter to Sugiura Gentō, the leader of the Ikkō-ikki in the Hokuriku region, in which he requested the Ikkō-ikki of Kaga and Etchū cooperate in opposition to Kenshin.  Shingen had a need to keep Kenshin in check to enable a march upon Kyōto without fear of attack from behind.  Therefore, Shingen requested Kennyo of the Ishiyama-Hongan Temple to have the Etchū Ikkō-ikki rebel against Kenshin.

In the fifth month of 1572, the Kaga Ikkō-ikki led by Sugiura Gentō (who was appointed as commander-in-chief by Kennyo) raised arms against Kenshin while members of the Shōkō and Zuisen temples that served as the base of the Etchū Ikkō-ikki at once joined the rebellion.  In 1567, Gentō invaded Echizen and won fame as a great commander in the battle against Asakura Yoshikage.  The Shōkō Temple was led by Kenei and the Zuisen Temple was led by Akihide, a seventh-generation abbot.  In addition, Shiina Yasutane and Jinbō Nagashiro (the son of Jinbō Nagamoto, a daimyō in Etchū) allied with the ikki forces.  In Kōzuke Province in the Kantō, Kenshin was in conflict with Takeda Shingen of Kai and Hōjō Ujimasa of Sagami so he could not himself join the fight against the invading forces.  Kawada Nagachika, a retainer of the Uesugi family in Etchū, dispatched Yoshie Tadakage to oppose the ikki forces.  On 5/19, Tadakage set-up a camp in the Ōta neighborhood.  The Etchū Ikkō-ikki converged with the Kaga Ikkō-ikki, swelling to a massive army of over 30,000 men.  On 5/23, these forces set-up a camp at Kawakami-Goishō.  The forward base of the Uesugi at Hinomiya Castle was subject to fierce attacks by ikki forces.  The defenders faced a crisis as provisions including gunpowder for their arquebuses ran low.  That same day, Jinbō Akihiro and Kojima Motoshige, in charge of protecting the castle, requested backup support from Ajisaka Nagazane of Shinjō Castle.

After deliberation by commanders of the Uesugi including Ajisaka Nagazane, Kawada Nagachika, and Sanponji Sadanaga, the forces marched west to aid the defenders of Hinomiya Castle, traversed the Jinzū River, and, on 6/15, clashed with the large army of ikki forces on Mount Gofuku in the Battle of Gofukuyama.  Despite making a valiant effort, the Uesugi was outnumbered by the ikki forces and withdrew.  While crossing the Jinzū River in retreat toward Shinjō Castle, the Uesugi were subject to a ferocious attack from behind by the Ikki forces and suffered a major defeat.  Without hope for reinforcements, the defenders at Hinomiya Castle surrendered and vacated the castle that same day, while Jinbō Akihiro and Kojima Motoshige fled to the Tenpyō Temple on Mount Sekidō.  Meanwhile, the ikki forces toppled Shiratori Castle on the west shore of the Jinzū River and Toyama Castle on the east shore of the river.

On 7/29, the ikki forces attacked the camp of Yamaura Kunikiyo (the eldest son of Murakami Yoshikiyo, the lord of Katsurao Castle in Shinano), whereupon Kawada Nagachika rushed to their aid and, although they killed several tens of the attackers, the Uesugi also incurred many casualties.  Owing to this series of major attacks, the ikki forces expanded their influence from the western portion to the central portion of Etchū Province.  Although the Uesugi army fought strenuously, having lost Hinomiya Castle, Shinjō Castle in the central portion of Etchū became the next front-line position and was also at risk of falling.

Deployment by Uesugi Kenshin

From Echigo, Kenshin was concerned about the status of the battles in Etchū.  In the seventh month, Hōjō Ujimasa invaded Kōzuke Province in the Kantō.  Kenshin responded by sending his adopted son, Nagao Akikage (later known as Uesugi Kagekatsu, a daimyō) to lead the Ueda group (the army of the Ueda-Nagao family).  On 8/6, Kenshin himself gave-up deploying to the Kantō and, instead, decided to deploy to Etchū.  At the entrance to Shinano, he positioned a unit of defenders to protect against an incursion by the Takeda army and, on 8/10, Kenshin personally led the main force of the Uesugi army of approximately 10,000 soldiers on a march toward Etchū.  On 8/18, Kenshin arrived at Yamanone in Shinjō, converging with Uesugi forces who had arrived earlier to form a large army with enough military power to resist the ikki army.  This began to give the Uesugi sufficient forces to recover from the earlier deficit vis-à-vis the ikki forces led by Sugiura Gentō who established a base in Toyama to attack Shinjō Castle.

On 9/13, in a letter that Kenshin sent to a retainer named Kuribayashi Masanori that the enemy army was massive.  Moreover, the ikki forces had a strong sense of solidarity based on their shared religious beliefs in the Ikkō sect.  As noted in letters in which Kenshin warned units of soldiers arriving later, the ikki forces possessed a lot of arquebuses so the defense of Shinjō Castle was precarious.  To resist the arrival of Kenshin, on 8/20, Sugiura Gentō requested Tsubosaka Kaneaki (Tsubosaka Hōki-no-kami), the head of the Kaga Ikkō-ikki located in the Kanazawa gobō, to send reinforcements from the two southern districts of Kaga (Nomi and Enuma).  On 8/31, Akihide, the abbot of the Zuisen Temple, notified Kaneaki that evening that a shooting battle had occurred, highlighting the ferocity of the battle.  There are no primary sources describing subsequent details of the actual battle.

At early dawn on 9/17,  the ikki forces at Toyama Castle folded their flags and began to withdraw toward Hinomiya Castle.  That evening, upon request of Kenshin, Ema Terumori, the lord of Takahara-Suwa Castle in Hida Province deployed to the battle and Yamaura Kunikiyo (later known as Kagekuni) came to meet him.  The Uesugi army traversed the Jinzū River and marched west.  On 9/18, Kenshin began an assault against Tatsuyama Castle which was aligned with the Ikkō-ikki.  The Uesugi army destroyed the castle walls so the Mizukoshi clan who were holed-up in the castle surrendered at the location of Kawada Nagachika.  Kenshin spared their lives while burning down the castle and, on 9/23, it was destroyed.  On 10/1, Toyama Castle fell.  On 10/18, Shiina Yasutane, an ally of the Ikkō-ikki, proposed surrender, but Kenshin refused and returned to Echigo.

Consequences of the battle

After a series of battles including Shiritarezaka resulting in their expulsion from the central portions of Etchū, the Ikkō-ikki forces from Kaga and Etchū experienced a decline in influence.  In the first month of 1573, the Ikkō-ikki made a peace proposal so Kenshin held peace negotiations at his camp in Etchū.  Based on these discussions, Shiina Yasutane requested via Nagao Akikage (later known as Uesugi Kagekatsu) and Kuribayashi Masayori another pardon from Kenshin, and it was given.

After securing Toyama Castle, Kenshin started on the road home, but, on the way, owing to the tactics of an assistant of Takeda Shingen named Miryō of the Enryaku Temple, the ikki forces occupied Toyama Castle.  Miryō was a member of the otogishū, personal assistants of their respective masters including the shōgun and daimyō.  Kenshin immediately turned back and took Toyama Castle by force, making Yasutane surrender again.  The ikki forces crossed the Jinzū River and fled in defeat.  As a result, the area to the east of the Jinzū River came completely under Kenshin’s control.  On 4/25, Kenshin returned to Echigo.

From the seventh to eighth months of 1573, Kenshin once again deployed to Etchū and crushed remaining enemies including the Shiina, the Jinbō, and the Ikkō-ikki.  By this time, Kenshin had pacified almost the entire province of Etchū.  Thereafter, while containing the movements of Hōjō Ujimasa of the Kantō, Kenshin marched west toward Kaga and Noto with an aim to march upon Kyōto.  Meanwhile, the Ikkō-ikki of Kaga and Etchū later settled on condition of abiding by Kenshin.  Thereafter, Oda Nobunaga became their common enemy.  After Sugiura Gentō (the commander-in-chief of the ikki forces at the Battle of Shiritarezaka) returned to Kaga, Asakura Yoshikage, the lord of Echizen, killed himself after being cornered by Oda Nobunaga.  The situation led Gentō to engage in numerous battles in Echizen.  In 1574, upon request of Kennyo, Gentō eliminated the former retainers of the Asakura and took control of the province.  As the district governor of Ōno, he became the lord of Iyama Castle in Echizen and, together with Shimotsuma Raishō (who was dispatched by Kennyo to serve as the military governor of Echizen), gave rise to the Echizen Ikkō-ikki.