The Mikawa Ikkō Uprising

Background — The Privileges of the Three Temples of Mikawa and Ieyasu's Drive for Centralization

Mikawa Province was home to powerful temples affiliated with the Hongan-ji order, namely Honshōji, Jōgūji, and Shōmanji, the so-called "Three Temples of Mikawa." These temples had been granted the privilege of shugoshi-fuiri since the time of Matsudaira Hirotada (Ieyasu's father), and they functioned as a kind of extraterritorial zone to which a lord's authority did not extend. After Imagawa Yoshimoto was killed at the Battle of Okehazama (1560) and Matsudaira Ieyasu freed himself from Imagawa rule, he rapidly sought to consolidate unified control over Mikawa Province. In this process, the privileges of the Three Temples emerged as an obstacle to Ieyasu's realization of control over the entire domain.

The trigger is said to have been an incident in Eiroku 6 (1563), when Ieyasu's retainer Suganuma Sadaaki forcibly requisitioned rice from Jōgūji to secure provisions. (There are various theories regarding the trigger, including an infringement of immunity rights at Honshōji.) Tensions between the temples and the Matsudaira side rapidly escalated. As rallying points for Hongan-ji followers, the Three Temples strongly opposed Ieyasu's push to strengthen his control, and the conflict eventually developed into armed clashes.

Among the Three Temples, Honshōji, which was especially influential even within the Hongan-ji order, had the structure of a "fortress-temple," with moats and earthen ramparts encircling it in multiple layers. Even in peacetime, it also functioned as a kind of military stronghold. The existence of such fortified temples across Mikawa was rooted in the strong religious communities of Jōdo Shinshū followers, which had spread widely throughout the Tōkai region since the time of Rennyo, the restorer of the Hongan-ji order. Under a strong sense of unity grounded in faith, the followers possessed a cohesion that did not readily yield even to lordly authority. This became the background to the Mikawa Ikkō Uprising's resistance, which was more stubborn than expected.

The Uprising Breaks Out and the Retainer Band Splits

In the 9th month of Eiroku 6, Hongan-ji followers centered on the Three Temples rose up, and the Mikawa Ikkō Uprising took full shape. Kūsei, the abbot of Honshōji, said to be a great-grandson of Rennyo, the restorer of the Hongan-ji order, became the spiritual pillar of the uprising forces. Leading the followers, he showed signs of pressing toward Ieyasu's stronghold, Okazaki Castle.

What made this uprising especially grave for Ieyasu was that it did not stop at a confrontation with a religious force. A considerable number of Ieyasu's own retainers, for reasons of faith, sided with the uprising. Among them were Honda Masanobu, who would later wield formidable influence as a senior retainer of the Tokugawa house, as well as Hachiya Sadatsugu and Natsume Yoshinobu, who also temporarily joined the uprising. This internal strife, which forced retainers to face the grave choice between their lord and their faith, was a crisis that could fundamentally shake the foundations of Ieyasu's power. At the same time, not a few retainers, like Ishikawa Kazumasa, though followers of Jōdo Shinshū, converted to Jōdo-shū, remained on Ieyasu's side, and upheld their loyalty to their lord.

Ieyasu's Defense and the Battle of Batōga-hara

While holding together his unsettled retainer band, Ieyasu continued to defend against the uprising forces' offensives. Ieyasu himself fought across various areas, seeking to break up the uprising forces. Ieyasu was still a young head of house in his early twenties at the time. Having just won independence from the Imagawa, he faced this internal strife from a precarious position, and it has also been described as a trial that tempered his later skill in governing. After nearly half a year of back-and-forth fighting, on the 15th day of the 1st month of Eiroku 7 (1564), the two sides fought a decisive battle at Batōga-hara (present-day Okazaki City, Aichi Prefecture), and Ieyasu's forces emerged victorious. Following this outcome, the momentum of the uprising forces rapidly waned, and the mood toward a peace settlement grew.

The Truce and Its Aftermath for Mikawa

Following their defeat at Batōga-hara, the uprising forces agreed to truce negotiations with Ieyasu. Ieyasu is said to have pardoned the retainers who had joined the uprising with leniency, keeping retaliatory punishment to a minimum. Through this truce, the Mikawa Ikkō Uprising, a conflict of roughly six months, came to an end. Regarding the interpretation of this pardon and truce, some view it as a political measure that, while appearing to confirm temple estates, in substance aimed to disarm the temples and strengthen control over them. Scholars have also pointed out that it should not be understood solely as a simple act of leniency.

After the truce, however, Ieyasu ordered the Three Temples and other Hongan-ji-affiliated temples to be demolished or converted to other sects, effectively banning Hongan-ji activity in Mikawa. This prohibition would continue for nearly twenty years, until Tenshō 11 (1583). Some of the retainers who had temporarily fled during the uprising were later permitted to return to Ieyasu's service, and some, like Honda Masanobu, were later valued as among Ieyasu's most trusted inner advisors.

Honda Masanobu is said to have left Mikawa after the suppression of the uprising and wandered through various provinces for a time. He was later recalled by Ieyasu and readmitted to his service. From then on, from Ieyasu's entry into the Kantō through the early years of the Edo shogunate, he was valued as an advisor in both domestic and foreign affairs. The course of a retainer who was at one point hostile later becoming a weighty figure as his lord's closest confidant is a good example showing that the Mikawa Ikkō Uprising was not merely a military internal strife. It also left a long-lasting impact on the later placement of personnel in the Tokugawa retainer band.

The Lesson the Mikawa Ikkō Uprising Left Ieyasu

The Mikawa Ikkō Uprising is an incident frequently cited in later times as one of the few crises of "retainer band split" that Ieyasu experienced in his lifetime. Although faced with the difficult situation of being caught between lord and faith, many retainers ultimately returned to Ieyasu and restored unity. This is evaluated as an example showing both the strength of Ieyasu's own power to draw loyalty and the skill of his flexible handling to overcome the crisis (forgiveness that avoided excessive reprisal). This experience is thought to have also influenced Ieyasu's later cautious approach to handling relations with religious forces in governing under Toyotomi rule and the Edo shogunate.

By overcoming the Mikawa Ikkō Uprising, Ieyasu finally established control within Mikawa Province, and thereafter he would earnestly embark on expanding his power toward Tōtōmi and Suruga. Alongside the Kaga Ikkō Uprising and the Nagashima Ikkō Uprising, the Mikawa Ikkō Uprising is one of the incidents symbolizing the tense relationship between the Hongan-ji order and daimyo power in the Sengoku period. It has remained an important case in research on Ikkō uprisings in early modern Japanese history.

Comparison with the Kaga Ikkō Uprising and the Nagashima Ikkō Uprising

Among the uprisings led by the Hongan-ji order and rising in the same Sengoku period are the Kaga Ikkō Uprising (in which Hongan-ji followers effectively established self-rule for nearly a century) and the Nagashima Ikkō Uprising, which long troubled Oda Nobunaga. Compared with these, the Mikawa Ikkō Uprising differed in character in that it ended within a short period of roughly half a year and did not reach the establishment of a long-term self-governing system encompassing the whole region. On the other hand, the Mikawa Ikkō Uprising had a distinctive character in that it strongly displayed the aspect of internal division, with a daimyo's own retainers turning away from their lord for reasons of faith. It has also been pointed out that this became one factor in Ieyasu's later cautious stance toward controlling religion. Within such comparisons, the Mikawa Ikkō Uprising is positioned as a unique case in the study of Ikkō uprisings.

Sites That Survive Today

Even today, in and around Okazaki City, Aichi Prefecture, the temple compounds of Honshōji, Jōgūji, and Shōmanji, the stages of the Mikawa Ikkō Uprising, remain and convey the memory of the fighting of that time to the present. At Honshōji, one can still see the structure of a fortress-temple with moats and earthen ramparts encircling it in multiple layers, making it a valuable historic site that illustrates how temples could also function as military strongholds. The precincts are designated as a national historic site, the main hall as a cultural property of Aichi Prefecture, and the drum tower (korō) as a cultural property of Anjō City. The site continues to welcome many visitors as a base for local historical education and regional history research. As one of the few hardships in Ieyasu's life, the Mikawa Ikkō Uprising has frequently been taken up in historical works, including the taiga drama, and it remains beloved today as a subject conveying the conflict between warriors and faith in Sengoku-period Mikawa.