were rebellious or autonomous groups of people that were formed in several regions of Japan in the 15th-16th centuries; backed up by the power of the Jōdo Shinshū sect of Buddhism, they opposed the rule of governors or daimyō. Mainly consisting of priests, peasants, merchants and local lords who followed the sect, they sometimes associated with non-followers of the sect. They were at first organized to only a small degree; if any single person could be said to have had any influence over them it was Rennyo, the leader of the Jōdo Shinshū Hongan-ji sect at that time. Whilst he may have used the religious fervour of the Ikkō-ikki in the defence of his temple settlements, he was also careful to distance himself from the wider social rebellion of the Ikkō movement as a whole, and from offensive violence in particular.
With recent improvements in firearms at the time, the Ikko-ikki movement would be able to rise very suddenly as a menacing force and which presented a credible threat to the government, as a peasant or merchant could transform himself into a capable mobile cannoneer in mere days.
History
According to Sansom, "The Ikko (Single-Minded) sect of Nenbutsu, or Buddha-calling ... is a branch of the worship of Amida developed from the teaching of Shinran into an aggressive doctrine of salvation by faith." In the 13th century, the jizamurai, a new class of small landowners, "formed leagues (ikki) for mutual defence", since they came from "good warrior families, long established in their own districts, and they were determined to protect their interests, both economic and social, against newcomers", according to Sansom. The Shirahata-Ikki, "White Flag Uprising", and Mikazuki-Ikki, "Crescent Uprising", were examples of the numerous risings against the Ashikaga shogunate. An uprising involving an entire province was called a Kuni-Ikki (kuni meaning province). Uprisings took place in 1351, 1353, 1369, 1377, 1384–1386, and 1366–1369. The risings in the 15th century, Tsuchi-Ikki or Do-Ikki, were better organized "and the peasants appear to have played a more prominent part". At the conclusion of the Ōnin War, in 1477, "many of the members of the numerous ikki" occupied the monasteries and shrines, and "would ring the warning bells day and night, hoping to terrify the rich citizens", according to Sansom.
The Ikkō-ikki were, at first, disparate and disorganized followers of Rennyo's teachings. His missionary work, and his appointment to the position of abbot of the Kyoto Hongan-ji, was in 1457, allowed him to "express in words and deeds" his unorthodox views. In 1465, Rennyo was forced to flee Kyoto, and established a new Hongan-ji branch temple, Yoshizaki-gobō, in Echizen Province in 1471. It was at this temple that he began to attract a significant following among peasants and farmers. About 1486 brought the first violent uprising, the first major organized action on the part of the Ikkō-ikki. They overthrew the governor of Kaga Province, and took control of it for themselves; this represented the first time in Japanese history that a group of commoners ruled a province.
The Ikko-ikki fought Asakura Norikage in the of 1506 and defeated Nagao Tamekage in the 1536 Battle of Sendanno. They fought Asakura Norikage again in the 1555 Battle of Daishoji-omote.
Rennyo was a pacifist and taught pacifism. He advocated self-defense only as a guard against the particularly tumultuous times in which he lived. Daimyō, samurai warlords, fought one another for territory nearly constantly, across the entire country. Rennyo thus saw to it that the temples of his sect were fortified and defended from attackers. Though it was his charismatic leadership and populist teachings that inspired the fervor which powered the Ikkō-ikki uprisings, he never advocated or supported them. The uprisings continued nevertheless, past Rennyo's death in 1499, and the sub-sect of Jōdo Shinshū that he had founded spread as well. They established themselves in fortresses at Ishiyama Hongan-ji, just outside Osaka, and in Nagashima, on the borders of Owari and Ise Provinces and in a series of temples in Mikawa Province as well.
Towards the end of the 16th century, however, their growing numbers and strength caught the attention and concern of the great samurai leaders of the time. Tokugawa Ieyasu worried that sōhei of Mikawa Province would rise up and seize the province. In 1564, his forces, with the help of Jōdo-shū sōhei, defeated the Mikawa Ikkō-ikki in the Battle of Azukizaka.