Ikkō-ikki

were armed military leagues that formed in several regions of Japan in the 15th–16th centuries, composed entirely of members of the Jōdo Shinshū sect of Buddhism. In the early phases, these ikki leagues opposed the rule of local shugo (governors) or daimyō (lords), but over time as their power consolidated and grew, they courted alliances with powerful figures in the waning Ashikaga shogunate until they were crushed by Oda Nobunaga in the 1580s.

Ikkō-ikki mainly consisted of priests, peasants, merchants, and jizamurai (local military rulers) who followed the sect, but they sometimes associated with non-followers. The ikkō-ikki included organisations of sōhei "monk warriors", similar to the lay or semi-lay military orders of medieval Christianity. They were at first only slightly organized. However, during the reforms of the monshu Jitsunyo and, later, under his grandson Shōnyo, the temple network enabled more efficient and effective troop mobilization when needed. The relationship between Hongan-ji and its monshu was complicated: some monshu, such as Rennyo, condemned the violence, others, such as Shōnyo and Kennyo, channelled it to further political aims. With improvements in matchlocks firearms (teppo) at the time, called Tanegashima, ikkō-ikki could suddenly rise as a menacing force, posing a credible threat to the government. A peasant or merchant could transform himself into a capable mobile cannoneer in mere days.