Siege of Iimori Castle
Date: 6/15 of Tenbun 1 (1532)
Location: The environs of Iimori Castle in the Sasara District of Kawachi Province
Synopsis: Forces sent by Hatakeyama Yoshitaka (the militay governor of Kawachi) who surrounded Iimori Castle were attacked from the rear by Ikkō-ikki forces from the Yamashina-Hongan Temple, causing them to flee in defeat.
Commanders: Hatakeyama Yoshitaka, Miyoshi Kazuhide
Forces: Hatakeyama forces, reinforcements from Miyoshi Motonaga
Losses: Over 200 near Iimori Castle on 6/15 and over 80 at the Kenpon Temple in Sakai on 6/20
The Siege of Iimori Castle occurred on 6/15 of 1532 in the early Sengoku period. Iimori Castle was located on Mount Iimori in the Sasara District of Kawachi Province. It was also referred to as Iimoriyama Castle.
Once Hosokawa Harumoto (an advocate of Ashikaga Yoshitsuna) held the reigns of power, it was believed that a momentary peace would hold in the capital. Nevertheless, a conflict between Hatakeyama Yoshitaka (the military governor of Kawachi who was backed by Miyoshi Motonaga) and Kizawa Nagamasa (the deputy military governor of Kawachi and the southern portion of Yamashiro and lord of Iimori Castle) triggered a new conflict.
The conflict originated from a struggle for control of Kawachi Province. Specifically, this involved the discovery of a plot by Nagamasa to wrest control of the position of military governor away from Yoshitaka. In the eighth month of 1531, Yoshitaka responded by relying upon Miyoshi Kazuhide (from the family of Miyoshi Motonaga) to attack Nagamasa at Iimori Castle, but, upon receiving a request from Nagamasa to send reinforcements, Hosokawa Harumoto issued orders for the attacking forces to withdraw, so Kazuhide stood down with his troops. Then, in the fifth month of 1532, after further preparations, Yoshitaka and Kazuhide attacked the castle again, and sought additional forces from Miyoshi Motonaga. Once again, Nagamasa requested reinforcements from Harumoto, but these were not sufficient to expel the joint forces of the Hatakeyama and Miyoshi.
Having abandoned the forcible removal of the opposing army by his own forces, Harumoto made a request to Shōnyo, the head priest of the Yamashina-Hongan Temple, to stir an uprising by the Ikkō-ikki – a religious band affiliated with the Jōdo sect of Buddhism. In this context, Motonaga skillfully exploited the followers of the Hongan Temple based on their sense of rivalry toward followers of the Hokke sect.
At the age of seventeen, Shōnyo broke the directive in the will of this grandfather, Jitsunyo, stating not to make enemies with bushi of other provinces. On 6/5 of 1532, he traveled from the Yamashina-Hongan Temple to Ōsaka and mobilized warrior monks from Settsu, Kawachi, and Izumi provinces. This amounted to a contingent of 30,000 troops. On 6/15, the ikki forces assaulted the army surrounding Iimori Castle from the rear, killing over 200 forces including Miyoshi Kazuhide, and pursuing Hatakeyama Yoshitaka during his retreat. On 6/17, Yoshitaka was cornered and killed himself.
Miyoshi Motonaga fled to take refuge at the Kenpon Temple – the base for the Miyoshi in Izumi Province, located in the city of Sakai. On 6/20, the ikki forces surrounded the temple while additional monks from throughout the region gathered, swelling the contingent to as many as 100,000 forces. In the wake of a bloodbath leading to the death of over eighty soldiers including Motonaga, the Ikkō-Ikki forces delivered a resounding victory to Harumoto. Although Nagamasa was also spared, continued rampaging by the Ikkō-Ikki monks in the wake of the uprising led to the Tenbun Conflict – a series of battles between the Hosokawa and Hatakeyama clans that persisted until 1535. Kizawa Nagamasa later died in fighting against the Hatakeyama and Miyoshi at the Battle of Taihei Temple on 3/17 of 1542.