The 1580 Battle of Omosu (Omosu no Tatakai) was one of many conflicts between the Hojo and Takeda clans during Japan's Sengoku period. What sets this battle apart is its rarity as one of the few naval engagements in pre-modern Japan. The conflict occurred off the coast of the Izu Peninsula, involving the fleets of Hojo Ujimasa, the leader of the Hojo clan, and Takeda Katsuyori, the head of the Takeda clan.
In a covert operation, the Fūma ninja, led by Fūma Kotarō, infiltrated and attacked a Takeda camp during the night. This surprise assault created chaos and confusion among the Takeda forces, leading them to turn on one another, causing significant casualties.
As the naval standoff continued, the land armies of both clans advanced towards each other. Ultimately, the Hojo clan emerged victorious.
See also
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The Siege of Tihaya Castle
Tihaya Castle was built by Kusunoki Masashige on top of Mount Kongo, separated from the neighboring hills by a deep ravine. The terrain itself provided natural protection, making the position extremely convenient for defense.
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The Siege of Akasaka Fort
Kusunoki Masashige, hero of the Genko Rebellion (1331–1333), was a talented commander and inventive strategist. The two sieges of castles where he acted as defender are inscribed in gold letters in the history of Japanese military art.
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The Battle of Itinotani
After the death of Minamoto no Yoshinaka, the Genpei War entered its final phase, which is closely associated with the name of Minamoto no Yoshitsune. On March 13, 1184, he and his brother Noriyori set out to accomplish what their cousin had failed to do: deliver a final defeat to the Taira.
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The Battle of Uji 1180
Minamoto no Yorimasa did not need a special pretext for his growing hostility toward the Taira clan to turn into open rebellion. The court also included the discontented Prince Motohito, the second son of the former Emperor Go-Shirakawa. He had already been passed over twice in the selection of the heir to the throne. The second time this happened was in 1180, when the young Antoku was enthroned. Thus, Kiyomori, the head of the Taira clan, became the emperor's grandfather.
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The Battle of Shigisan
The conflict between the Soga and Mononobe clans, who were related to the imperial dynasty, arose on religious grounds. The Soga supported Buddhism, which had come from Korea, while the Mononobe remained faithful to Shintoism and fiercely opposed the spread of “foreign teachings.” Tensions reached a peak after the death of Emperor Yomei in 587.
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The Mongol invasion of Japan
At the end of the 13th century, Japan faced a danger far more serious than any internal strife. In 1271, the Yuan dynasty, founded by Kublai Khan, grandson of Genghis Khan, established itself in China. His army was truly enormous: tens of thousands of soldiers — Chinese, Koreans, Jurchen, and especially Mongols, who had conquered the territory from Korea to Poland and from the northern taiga to Egypt. Only one country remained unconquered — Japan.
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The Genpei War
As early as the 8th century AD, Japanese emperors gradually lost their real power and became symbolic figures, under the complete control of the powerful Fujiwara clan. This clan, by marrying their daughters to emperors, effectively monopolized the government of the country: all key military and administrative positions were held by representatives of the Fujiwara.
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The Rebellion of Fujiwara no Hirotsugu
Fujiwara no Hirotsugu was the son of Fujiwara no Umakai, one of the most important court officials of the Nara period. By 740, the Fujiwara clan had held the reins of government for several decades. However, in 735–737, Japan suffered a severe trial: the country was hit by a devastating smallpox epidemic. It coincided with a series of crop failures, and together, disease and famine claimed the lives of about 40% of the population of the Japanese islands. The consequences were particularly tragic for the aristocracy. The mortality rate among the court nobility exceeded that among the common people. All four Fujiwara brothers, who held the most important positions at court — Umakai, Maro, Mutimaro, and Fusasaki — died.
