
The Buddhist peasant movement Ikko-Ikki, which emerged in the 15th century, had grown considerably stronger and larger by the middle of the following century. It had effectively turned into a large feudal army used for territorial conquests. The Ikko-ikki fought fiercely not only against other branches of Buddhism, but also against the provincial daimyo and the central government.
Distinguished by their fanatical devotion to their faith and confident that after death they would be reborn in the “Pure Land,” the sectarian warriors fought fiercely and mercilessly. They spared neither the lives of others nor their own.
From 1488, the Ikko-ikki controlled the province of Kaga and exerted a strong influence on the neighboring province of Etizen. In 1533, they fortified the Ishiyama Honganji monastery in the province of Settsu. Later, they established themselves in a number of temples in Mikawa Province, and in 1555, they defeated Daimyo Ito Shigeharu at his castle near Nagoya and created a chain of fortifications there under the general name of Nagashima.
Geography and fortifications of Nagashima
The area where Nagashima was located was a marshy delta of three rivers: Kiso, Nagara, and Ibi. All of them flowed into Ise Bay on the border between the provinces of Owari and Ise. One large oblong island probably gave the area its name (Nagashima literally means “long island”). This island still exists today, while many of the small islands described in 16th-century sources have disappeared from the map. Some islands were protected from flooding by dams and were called waju.
The Nagashima fortifications stretched along the coast. They included two main strongholds—Nagashima Castle and Ganshoji Monastery—as well as several smaller forts that controlled the approaches to the main defensive points.
The fortifications did not have stone walls. They were based on palisades, fences, earthen walls, and watchtowers.
Nature itself served as a reliable shield: it was extremely difficult to storm such a fortress. In addition, the defenders created artificial obstacles. Old clay pots were buried in the thick reeds that covered the banks, which could easily be kicked and broken an ankle. They also drove stakes into the ground and stretched ropes between them, creating a kind of trap against cavalry.
Nobunaga's personal motive and the beginning of the campaigns
The presence of a fortified camp of rebellious Ikko-ikki in his native province of Owari greatly irritated Oda Nobunaga. The situation was exacerbated when his younger brother, Oda Nobuoki, was killed by sectarians from Nagashima. From that moment on, in addition to political reasons, Nobunaga had a personal motive for destroying this stronghold of fanatics.
The sieges of Nagashima were conducted in parallel with the siege of the main center of the Ikko-ikki, the Ishiyama Honganji monastery. They lasted for three campaigns.
The first siege (1571)
In 1571, Nobunaga entrusted the siege of Nagashima to two of his experienced commanders, Sakuma Nobumori and Shibata Katsuie. The Oda clan's troops approached the fortifications from the northeast and set up camp.
At a military council, it was decided to attack the small islands of Wajū and then strike Hanshōji Temple. But difficulties arose at the very first stage: when attempting to cross a shallow river on horseback, the samurai encountered sticky bottom silt. The horses refused to move, got stuck, and threw off their riders.
Those who managed to get ashore were blocked by rope barriers. At this time, heavy fire began from the reeds: the Ikko-ikki used bows and arquebuses.
The sectarians had already achieved considerable success in the use of firearms. Moreover, some of their tactical techniques were later adopted by Nobunaga himself.
The failures were compounded by the destruction of the dams: many samurai of the Oda clan, who were trapped on the waju, drowned. Shibata Katsuie himself was wounded. The Oda troops had to retreat, abandoning the siege. During their retreat, they managed to set fire to several settlements, but this only provoked even greater hatred from the local residents.
Second siege (1573)
In 1573, Nobunaga himself led the second siege of Nagashima. By this time, he was finally convinced of the effectiveness of the mass use of arquebuses and relied on heavy gunfire.
According to the plan, Sakuma Nobumori and Toyotomi Hideyoshi were to carry out diversionary attacks from the west, while Nobunaga and the main army were to force the river under the cover of a large number of arquebusiers.
However, at the moment the assault began, a thunderstorm broke out with heavy rain. The samurai's gunpowder got wet, and their weapons became useless. The Ikko-ikki, on the other hand, managed to keep their gunpowder dry. When the rain began to subside, they opened massive fire on the attackers and nearly killed Nobunaga himself. The besiegers were forced to retreat.
At the same time, Takigawa Kazumasu's detachment managed to capture Yata Fort on the southern edge of the fortifications, but it was soon recaptured as a result of a counterattack by the sectarians.
Third siege (1574)
In 1574, Nobunaga gathered even more troops and launched a third siege of Nagashima. This time, his trump card was Admiral Kuki Yoshitaka (1542–1600) and his fleet.
Yoshitaka established a naval blockade, completely cutting off supply routes. His ships effectively bombarded the fortifications with grapeshot and incendiary arrows, concentrating their fire on the wooden towers.
Nobunaga's troops managed to capture the outer forts of Nakae and Yanagashima, which allowed them to approach the main fortifications from the west. In the next attack, coordinated with the actions of the fleet, Nobunaga launched three strikes from the north, pushing the defenders back to the very center — the castle and monastery.
Further fighting ceased: Nobunaga completely cut off supplies of food, weapons, and men. About 20,000 people were surrounded. Famine set in, and soon the first victims appeared in Nagashima. Attempts by allies to break the blockade from the outside failed.
The sectarians appealed to Nobunaga for negotiations, but he refused. He was only satisfied with the complete destruction of his enemies.
The fire and destruction of Nagashima
Nobunaga's warriors built a wooden wall between the forts of Nakae and Yanagashima. Under its cover, they prepared a huge amount of brushwood. Waiting for a strong wind to blow towards the fortifications, the samurai set fire to the brushwood.
The flames quickly spread across the strait and engulfed all the buildings of the Ikko-Ikki. As he had done earlier with the temple on Mount Hiei, Nobunaga dealt mercilessly with the religious fanatics. All the inhabitants of Nagashima, both warriors and civilians, burned to death in the fire.
See also
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Battle of Tennoji

The confrontation between Tokugawa Ieyasu and Toyotomi Hideyori during the “Osaka Winter Campaign” ended with the signing of a peace treaty. On January 22, 1615, the day after the treaty was signed, Ieyasu pretended to disband his army. In reality, this meant that the Shimazu forces withdrew to the nearest port. On the same day, almost the entire Tokugawa army began filling in the outer moat.
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Siege of Shuri Castle

The Ryukyu Kingdom was established in 1429 on Okinawa, the largest island of the Ryukyu (Nansei) archipelago, as a result of the military unification of three rival kingdoms. In the following years, the state's control spread to all the islands of the archipelago.
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The Siege of Fushimi Castle

Fushimi can perhaps be considered one of the most “unfortunate” castles of the Sengoku Jidai period. The original castle was built by Toyotomi Hideyoshi in the southeast of Kyoto in 1594 as his residence in the imperial city.
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The Siege of Otsu Castle

The siege of Otsu Castle was part of the Sekigahara campaign, during which the so-called Eastern Coalition, led by Tokugawa Ieyasu, fought against the Western Coalition, led by Ishida Mitsunari. Otsu Castle was built in 1586 by order of Toyotomi Hideyoshi near the capital Kyoto, on the site of the dismantled Sakamoto Castle. It belonged to the type of “water castles” — mizujō — as one side of it faced Japan's largest lake, Lake Biwa, and it was surrounded by a system of moats filled with lake water, which made the fortress resemble an island.
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The Siege of Shiroishi Castle

The siege of Shiroishi Castle was part of the Sekigahara campaign and took place several months before the decisive battle of Sekigahara. The daimyo of Aizu Province, Uesugi Kagekatsu, posed a serious threat to Tokugawa Ieyasu's plans to defeat the Western Coalition, and Ieyasu decided to curb his actions with the help of his northern vassals. To this end, he ordered Date Masamune to invade the province of Aizu and capture Shiroishi Castle.
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The Second Siege of Jinju Castle

During the two Korean campaigns of the 16th century, the Japanese repeatedly had to capture enemy fortresses and defend occupied or constructed fortifications from the combined Korean and Chinese forces. Among all the operations of that time, the second siege of Jinju Castle is considered the most interesting from the point of view of siege warfare.
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The Siege of Takamatsu Castle

The siege of Takamatsu Castle in Bitchu Province is considered the first mizuzeme, or “water siege,” in Japanese history. Until then, such an original tactic had never been used.
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The Third Siege of Takatenjin Castle

The history of the castle prior to the conflict between the Tokugawa and Takeda clans is rather unclear. According to one version, the castle was built in 1416, when Imagawa Sadayoshi (1325–1420) was governor of Suruga Province and half of Totomi Province. Allegedly, it was he who ordered Imagawa Norimasa (1364–1433) to build this fortification. However, no reliable evidence has been found to support this. Another version is considered more plausible, according to which the castle was built during the conquest of Totomi Province at the end of the 15th century by Imagawa Ujitsuna (1473–1526) and his general Ise Shinkuro (Hojo Soon). In this case, another of Ujitsuna's generals, Kusima Masashige (1492–1521), is considered responsible for the construction.
