The Rise of Rival Warlords in 16th-Century Japan
The year 1564 marked the peak of Uesugi Kenshin’s military dominance as Kanto Kanrei (Shogunal Deputy of Eastern Japan). Since his southward expansion into Kanto in 1561, Kenshin had relentlessly campaigned against the Later Hōjō clan, stifling their territorial ambitions. In Shinano, his four brutal battles with Takeda Shingen at Kawanakajima checked the latter’s northward advance. Meanwhile, in Etchū, Kenshin steadily expanded his influence, following his father Nagao Tamekage’s footsteps. Even in Ugo-Oshu, he repelled invasions by Ashina Morihiro, who had allied with Takeda and Hōjō. For a time, Kenshin fought on all fronts without faltering—until an unexpected plea for help arrived from the mountainous region of Hida.
The Sister Road to Conflict: Alliances and Betrayals
The lord of Hida, Anekōji Yoritsuna (born into the local Miki clan), had secured imperial approval in 1562 for his son to inherit the prestigious Anekōji name. By 1564, however, rival clan Ema Tokishige allied with Takeda Shingen, who dispatched his famed general Yamagata Masakage and son-in-law Kiso Yoshimasa to attack Anekōji. Forced into submission, Yoritsuna sought vengeance through an alliance with Takeda’s nemesis: Uesugi Kenshin.
When Takeda Shingen learned of this betrayal, he struck back in Hida. In response, Kenshin launched his fifth campaign into Kawanakajima, diverting Takeda’s forces and relieving pressure on Anekōji. Meanwhile, Shingen invited eastern Mino lords like Toyama Kagetsuna and Naegi Nobusada to join his campaign—alarming Oda Nobunaga, who feared Takeda’s westward expansion.
The Fracturing of Alliances: The Yoshinobu Incident
In October 1565, Takeda Shingen’s world shattered when his heir, Yoshinobu, was implicated in a plot to assassinate him. The conspiracy, led by Yoshinobu’s tutor Obu Toramasa, exposed deep fractures within the Takeda clan. Yoshinobu resented his father’s favoritism toward his fourth son, Katsuyori, and opposed abandoning the alliance with the declining Imagawa clan (his wife’s family).
Shingen’s brutal suppression of the plot—executing Toramasa and exiling 80 retainers—masked a precarious reality. The Takeda-Imagawa-Hōjō alliance (the “Triple Alliance”) was crumbling. Shingen’s secret negotiations with Oda Nobunaga (sealed by Katsuyori’s marriage to Nobunaga’s niece) signaled his intent to betray Imagawa. Yet Yoshinobu’s faction remained powerful, forcing Shingen to bide his time.
The Collapse of Kenshin’s Eastern Campaigns
While Takeda dealt with internal strife, Uesugi Kenshin faced disaster in Kanto. His 1566 siege of Usui Castle—a strategic link to ally Satomi Yoshihiro—ended in humiliation. Despite outnumbering defenders 7-to-1, Kenshin’s forces were repelled by a desperate counterattack led by commander Shirai Nyūdō Jōsan. The defeat triggered a domino effect: former allies like Utsunomiya and Oda clans defected to Hōjō. By 1567, even Kenshin’s key general Hōjō Takahiro switched sides.
As Kenshin’s influence crumbled, Takeda Shingen seized western Kōzuke, annihilating Nagao Narimori at Minowa Castle. The once-mighty Uesugi now stood isolated, his prayers for peace with Hōjō unanswered.
The Fall of Imagawa and the Race for Suruga
With Kenshin neutralized, Shingen turned south. The Imagawa clan, weakened since their 1560 defeat at Okehazama, lost Mikawa to Tokugawa Ieyasu and faced revolts in Tōtōmi. In December 1568, Shingen launched a lightning invasion of Suruga, crushing Imagawa Ujizane’s forces at Satta Pass. Ujizane fled to Hōjō-protected Odawara, while Shingen occupied Sunpu—only to face a new threat: the revived Hōjō-Uesugi alliance.
The Three-Way Struggle: Shingen’s Gambit
In 1569, Hōjō Ujiyasu and Kenshin forged an unlikely pact against Takeda. Shingen countered by striking at Odawara itself, feigning retreat through the deadly Misaka Pass. There, his forces annihilated pursuing Hōjō troops in the Battle of Mimasetoge (October 6, 1569), showcasing his tactical genius.
Yet the war’s tide turned in 1570 when Ujiyasu’s death led his son Ujimasa to reconcile with Shingen. The “Kōsō Peace” restored their alliance, isolating Kenshin once more. With eastern threats neutralized, Shingen set his sights west—toward Tokugawa Ieyasu and Oda Nobunaga.
Legacy: The Dawn and Twilight of Takeda Ambitions
Shingen’s 1572 invasion of Tōtōmi marked his zenith—his innovative tactics crushing Ieyasu at Mikatagahara. Yet his sudden death in 1573 left the campaign unfinished, and his son Katsuyori’s disastrous defeat at Nagashino (1575) doomed the Takeda.
The 1564-1572 period reshaped Japan’s balance of power:
– Uesugi Kenshin’s overextension proved even legendary commanders have limits.
– Takeda Shingen’s betrayal of Imagawa demonstrated ruthless pragmatism.
– The Hōjō clan’s resilience showed diplomacy could outlast battlefield defeats.
Ultimately, Shingen’s maneuvers—from crushing his heir to conquering Suruga—paved the way for Oda Nobunaga’s rise. His story remains a masterclass in Sengoku-era strategy: a blend of military brilliance, political cunning, and the relentless pursuit of power at any cost.