The Northern Fujiwara clan had governed the Mutsu and Dewa provinces since 1087, maintaining their rule for over a century by 1189. The clan was founded by Fujiwara no Kiyohira, alongside Minamoto no Yoshiie, who established their independence in Hiraizumi, located in present-day Iwate Prefecture. Under Kiyohira, and later his successors Fujiwara no Motohira and Fujiwara no Hidehira, the Northern Fujiwara reached the height of their power in the Tohoku region. They infused the area with Kyoto culture and constructed significant temples, such as Chuson-ji, founded in 1095.
During the Genpei War (1180-1185) between the Minamoto and Taira clans, the Northern Fujiwara remained neutral. Even after the Minamoto's victory and the Taira's destruction in 1185, the Northern Fujiwara continued their policy of neutrality, refraining from involvement in the conflict.
The Battle of Oshu was triggered by a dispute over the extradition of Minamoto no Yoshitsune, who had fled to Hiraizumi. Although Hidehira had remained neutral during the Genpei War, he chose to protect Yoshitsune when he sought refuge, straining relations between the Northern Fujiwara and Minamoto no Yoritomo, ultimately leading to a confrontation.
After Hidehira's death, his son, Fujiwara no Yasuhira, became the fourth head of the Northern Fujiwara clan. Under pressure from Yoritomo, Yasuhira ordered Yoshitsune’s assassination during the Battle of Koromo River on June 15, 1189. Yoshitsune's severed head was delivered to Kamakura on July 7, where it was inspected by Wada Yoshimori and Kajiwara Kagetoki. Despite an imperial order from Emperor Go-Shirakawa on July 22 to halt hostilities, Yoritomo was already committed to attacking Hiraizumi, and the order did nothing to mend the broken relationship.
On August 8, Yoritomo petitioned the Imperial Court in Kyoto to authorize a punitive expedition against Fujiwara no Yasuhira. The following day, a revolt in Oshu led to the death of Fujiwara no Tadahira, a supporter of Yoshitsune, the son of Hidehira. On August 30, Yoritomo discussed the conquest of Oshu with his general, Oba Kageyoshi.
However, before the court could issue a decision, Yoritomo launched the expedition independently. According to the Azuma Kagami, he mobilized 284,000 cavalrymen from over 60 provinces across Japan, including southern Kyushu, all converging to attack Hiraizumi. Meanwhile, Yasuhira assembled an army of 170,000 cavalrymen in preparation.
On August 30, Yoritomo and his forces spent the entire day planning the assault, dividing his army into three groups: the Tokaido, Ote, and Hokurikudo forces. The next day, the Hokurikudo forces departed Kamakura. On September 1, Yoritomo, leading the central Ote forces, also set out from Kamakura, advancing north. Along the way, a prisoner from Echigo Province, Jo Nagamochi, joined their ranks.
The central forces, commanded by Yoritomo himself, reached Kotahashi Station in Shimotsuke Province on September 7, where Yoritomo offered a ritual wand to the gods at Utsunomiya Shrine. The following day, he continued north, adding Satake Hideyoshi from Mutsu Province to his army. On September 10, Yoritomo arrived at Nitobe Station, where over 200 retainers of Jo Nagamochi joined the campaign.
On September 11, Yoritomo's forces breached the Shirakawa Barrier, and by September 18, they arrived at Kunimi Station. On September 19, Yoritomo clashed with the Northern Fujiwara forces at Mount Atsukashi, leading to subsequent battles at Ishinazaka and Nenashifuji. These encounters resulted in the deaths of Fujiwara no Kunihira, Kongo no Betto Hidetsuna, Sato Motoharu, and Sato Kinjuro. Yoritomo's forces triumphed on September 21 and continued their advance. The next day, Yoritomo inspected Kunihira's head at Funabasama.
By September 23, Yoritomo's forces had captured Taga Castle in Mutsu Province and joined with the Tokaido forces. Yasuhira was compelled to abandon his primary military base at Kokubugahara Muchidate (in present-day Tsutsuji-gaoka, Sendai). On September 24, the Hokurikudo forces defeated Tagawa Yukibumi and Akita Munebumi in Dewa Province. On September 25, Yoritomo's retainer Oyama Tomomasa crushed the Northern Fujiwara forces at Monomigaoka, allowing Yoritomo to advance to Takahaba Castle in Tamatsukuri. On October 1, Yoritomo captured Takahaba Castle and pushed forward towards Hiraizumi. Yasuhira, unable to defend his capital, abandoned Hiraizumi and set it ablaze on October 2.
Yoritomo entered the scorched remains of Hiraizumi on October 3, defeated the remaining forces, and seized Hiraizumi Castle. On October 6, Fujiwara no Motonari and his sons surrendered at Koromo River Palace. The next day, Yoritomo received a letter from Yasuhira indicating a willingness to surrender. However, on October 13, Yoritomo began a manhunt for Yasuhira at the Kuriyagawa Barrier in Iwate. The following day, Yasuhira was captured by Yoritomo's forces north of Hiraizumi and killed by Kawada Jiro in Nienosaku, Hinai, Mutsu Province (now Odate, Akita Prefecture).
The Battle of Oshu concluded with Minamoto no Yoritomo's decisive victory and the defeat of the Northern Fujiwara. This marked the end of the civil war that began in 1180 and solidified Yoritomo's nationwide control through the annexation of Mutsu and Dewa provinces, leading to the establishment of the Kamakura shogunate.
After Yasuhira's death, Yoritomo's forces, along with the Hokurikudo troops, arrived at Jingaoka in Shiwa on October 15, 1189. Two days later, Kawada Jiro presented Yasuhira’s severed head to Yoritomo. Following the custom from the Former Nine Years' War, Yoritomo displayed the head by nailing it in place.
On October 18, Yasuhira's loyal attendant, Yuri Korehira, was captured. Impressed by Korehira's bravery, Yoritomo remarked, "Yasuhira held power in Oshu, and I thought it would be difficult to defeat him, yet Kawada Jiro alone ended his life because he lacked a worthy attendant. Despite ruling two provinces and leading 170,000 cavalrymen, his entire clan fell within 20 days. The rest is insignificant." Korehira replied, "The former Head of the Left Division of the Bureau of Horses ruled fifteen provinces along the Tokaido but could not withstand a single day during the Heiji Rebellion and was killed by Nagata Tadamune, though he commanded tens of thousands of cavalrymen. Can we truly judge superiority or inferiority between past and present? Yasuhira commanded only a small number of warriors from two provinces, yet he resisted Lord Yoritomo for many days. It is not easy to draw conclusions."
On October 19, Yoritomo dispatched a courier to Kyoto to announce his victory. Although the Imperial Court had not approved Yoritomo’s request during the battle, it issued a retroactive order of approval after the conflict ended. On October 20, Ichijo Yoshiyasu sent a court order from Kyoto for the punitive expedition against Yasuhira, dated September 1, 1189, to Yoritomo at Jingaoka.
On October 22, Yoritomo left Jingaoka to stay at the Kuriyagawa Barrier. Eight days later, he moved to Hiraizumi, where he appointed Kasai Kiyoshige as Magistrate (bugyo) of Mutsu Province. After solidifying his control, Minamoto no Yoritomo and his forces departed from Oshu and returned to Kamakura on November 8, 1189.
See also
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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.
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Battle of Mimigawa
In 1556, the Shimazu clan launched a campaign aimed at systematically conquering the island of Kyushu. In the same year, the province of Osumi was annexed and a war began with the Ito clan for control of the province of Hyuga. In 1577, Ito Yoshisuke was defeated and fled north, where he sought help from Otomo Sorin, the Christian daimyo of Bungo Province.
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The Siege of Kozuki Castle
The battle for Kozuki Castle was a consequence of Oda Nobunaga's expansion in the Chugoku region. Toyotomi Hideyoshi was appointed to lead the campaign, which aimed to weaken the influence of the Mori clan in these lands. Under his command were famous samurai: Kuroda Kanbei, Takenaka Shigeharu, and Hachisuka Koroku. Amago Katsuhisa, who cherished the hope of one day restoring the Amago clan's lost dominance in western Japan, also joined Oda's army.
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The Siege of Nagashino Castle
Despite his reputation as a failure, created by 20th-century popular culture, especially cinema, Takeda Katsuyori (1546–1582) was in fact a brave warrior and talented commander. However, he always remained in the shadow of his great father, the legendary Takeda Shingen. After Shingen's death, Katsuyori sought to at least equal him, if not surpass him. Therefore, his actions were not always determined by pragmatic calculation. This character trait greatly influenced the subsequent events that led to the demise of the Takeda clan.
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Siege of Nagashima Fortifications
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.
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The Second Battle of Konodai
Hojo Ujiasu (1515–1571), one of the greatest representatives of the Hojo clan, spent almost his entire life at war. His possessions were in a difficult position: they were surrounded on all sides by aggressive neighbors ready to attack at any moment. In implementing his plans to expand the Hojo clan's influence in the Kanto region, Ujiasu was forced to confront well-known and powerful opponents—the Uesugi and Takeda clans. In the east, his main rival was the Satomi clan.
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The Fourth Battle of Kawanakajima
The Kawanakajima Plain is located at the confluence of the Saigawa and Tikumagawa rivers in the Japanese Alps. Between 1553 and 1564, five battles took place on this plain between the forces of Uesugi Kenshin and Takeda Shingen.
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Battle of Tonamoto (Nagahama)
At the beginning of the Sengoku Jidai period, the Teshokabe clan was one of the smaller clans in Tosa Province. Its neighbors were constantly at war with each other, engaging in endless skirmishes. Among them, Yosokabe Kunitika stood out as a military strategist of extraordinary talent. It was thanks to these abilities that he managed to defeat the neighboring clans step by step by the middle of the 16th century, expanding the influence of his clan. At that time, the clan's headquarters was Oko Castle.
