Ikkō-shū

The Ikkō-shū (一向宗), often translated as the "Single-Minded Sect," was a popular and influential branch of Jōdo Shinshū (Pure Land Buddhism) in medieval Japan. While officially a part of the Jōdo Shinshū lineage, its followers developed a distinctive socio-political identity, often characterized by peasant uprisings and a degree of autonomy from traditional feudal lords.

The name "Ikkō-shū" itself was used loosely to describe followers of Rennyo (1415-1499), the 8th monshu (head priest) of the Hongan-ji temple. Rennyo's efforts to spread the Jōdo Shinshū teachings amongst the common people, writing in accessible vernacular Japanese and emphasizing simple faith in Amida Buddha, were immensely successful. He stressed the importance of shinjin (entrusting), the absolute reliance on Amida's saving power.

However, the enthusiastic devotion and growing numbers of Rennyo's followers sometimes led to friction with established Buddhist institutions and the ruling samurai class. This was due, in part, to the egalitarian nature of the teachings, which challenged the hierarchical structure of feudal society. The Ikkō-shū built fortified temples, known as garan, which became centers of resistance against local lords.

The most significant example of Ikkō-shū power was the establishment of a virtual theocracy in Kaga Province (modern-day Ishikawa Prefecture) in the late 15th century. Followers, largely peasants and lower-ranking samurai, ousted the provincial governor and established a self-governing entity centered around the Hongan-ji temple in Yoshizaki. This "Ikkō-ikki" (single-minded league) state persisted for nearly a century.

Ikkō-ikki uprisings also occurred in other regions, including Mikawa, Echizen, and Settsu, often involving intense fighting and prolonged sieges. These uprisings represented a significant challenge to the authority of the central government and various daimyō (feudal lords) during the Sengoku period (Warring States period).

Oda Nobunaga, a powerful daimyō seeking to unify Japan, considered the Ikkō-shū a major obstacle. He engaged in a lengthy and brutal campaign against them, culminating in the siege and destruction of the Ishiyama Hongan-ji temple in Osaka in 1580, a key stronghold of the Ikkō-shū.

Despite Nobunaga's efforts, the Ikkō-shū survived. After Nobunaga's assassination, Toyotomi Hideyoshi, his successor, allowed the rebuilding of the Hongan-ji temple in Kyoto. The movement subsequently split into two main branches: the Honganji branch (Nishi Honganji) and the Ōtani branch (Higashi Honganji). These branches continue to be major forces within Jōdo Shinshū Buddhism today.