How a failed imperial coup ended a century of military rule in Japan
Between 1331 and 1333, Emperor Go-Daigo attempted to dismantle the Kamakura Shogunate to restore civilian imperial power. What began as a desperate, betrayed rebellion transformed into a total collapse of the Hōjō regency, forever altering the trajectory of Japanese governance and leading to the rise of the Ashikaga Shogunate.
The Genkō War was sparked by Emperor Go-Daigo’s ambition to reclaim authority from the Kamakura Shogunate, a military government that had effectively controlled Japan since 1185. The shogunate, managed by the Hōjō clan, had long stifled the Imperial House in Kyoto. In 1331, Go-Daigo’s initial plot to overthrow the regime was thwarted by a betrayal from his adviser, Fujiwara Sadafusa. Following a failed defense at the monastery of Kasagi, the Emperor was captured and exiled to the Oki Islands, while the shogunate installed a puppet ruler, Emperor Kōgon, to solidify their control.
The tide turned in 1333 when Go-Daigo escaped exile and rallied a new army at Mount Senjō. The conflict reached a critical turning point when Ashikaga Takauji, a high-ranking Hōjō general, defected to the Imperial side. While his motivations remain debated, historians suggest his allegiance to the Minamoto clan—historic rivals of the Hōjō’s Taira lineage—or a desire for the title of Shōgun likely drove his betrayal. With the support of commanders like Nitta Yoshisada, who secured a series of decisive victories in the Kōzuke–Musashi campaign, the Imperial forces eventually breached Kamakura in July 1333, forcing the Hōjō leadership to commit suicide.
Go-Daigo’s victory, known as the Kenmu Restoration, was short-lived. His attempt to centralize power alienated the very samurai and commoners who had fought for his return. By excluding these groups from political influence and failing to address their grievances, Go-Daigo undermined his own administration. By 1336, Ashikaga Takauji seized power for himself, establishing the Ashikaga Shogunate. This transition effectively dismantled the restoration and ushered in the Nanboku-chō period, characterized by the competing Northern and Southern Courts, leaving the dream of civilian imperial rule largely unrealized.
Source: Genkō War
