Stories of the Japanese 01258 [Muromachi Period/Yoshimitsu Era]: The First Rebellion of Date Masamune and the Inamura Kubo

The shogunate had been considering how to deal with Kamakura Kubo Mitsukane, who had attempted to raise an army in response to Yoshihiro, but they soon had bigger problems to worry about. Shortly after the end of the Oei Rebellion, Date Masamune (1353–1405) launched a rebellion in the Tohoku region. From here, I will recount the circumstances of the Date Masamune Rebellion.
In late July of the 6th year of Oei (1399), just before the Oei Rebellion, Mitsukane had sent his younger brother Mitsusada (1390–1439) to Inamura (Sukagawa City, Fukushima Prefecture) to oversee the Oshu region. Mitsusada came to be known as the 'Inamura Kubo'.
The second Kamakura Kubo, Ashikaga Ujimitsu, had previously crushed the Oyama and Oda clans in order to expand his territory, and the Inamura Kubo, Mitsusada, was also an ambitious man. He demanded that the Date clan, based in Okitama (Yonezawa City, Yamagata Prefecture), cede their territory.
The head of the Date clan at this time was Masamune. When people hear the name Date Masamune, many likely imagine the famous Sengoku period warlord known by the nickname 'One-Eyed Dragon,' but the Date Masamune appearing here is a different person of the same name who was his eighth-generation ancestor.
Date Masamune attempted to offer up the 33 villages of Nagai Hojo in Dewa Province (Nagai City, Yamagata Prefecture), but Mitsusada's response was that the scale was insufficient. If one were to endlessly comply with such unreasonable demands, it would be impossible to protect one's land and people. Date Masamune called upon influential clans in the surrounding area, gained the support of Ashina Mitsumori and others, and raised an army. This was the beginning of the First Date Masamune Rebellion.
On March 8th of the 7th year of Oei (1400), Inamura Kubo Mitsusada ordered his subordinate, Yuki Mitsutomo, to suppress Date Masamune and Ashina Mitsumori.
In response to Date Masamune's call, an even bigger figure than expected also joined in: the former Oshu Kanrei, Osaki Akimochi (died 1400). Since the time when Shiba Takatsune's younger brother, Iekane, was appointed Oshu Kanrei (see episode 01084), the Osaki family had held the position of Oshu Kanrei for two generations, with Naomochi and then Akimochi. Akimochi had served the Ashikaga family well, such as by suppressing the rebellion of Hatakeyama Kuniaki in the 3rd year of Bunchu/7th year of Oan (1374), so he likely could not tolerate having his authority usurped by this newcomer, the Inamura Kubo. Incidentally, it was around this time that the title 'Oshu Kanrei' was changed to 'Oshu Tandai'.
Akimochi, who had been stationed at the Kamakura-fu when the rebellion began, fled Kamakura in September and headed toward Mutsu to join Date Masamune. However, on his way to his own territory of Osaki (Osaki City, Miyagi Prefecture), he had to pass through the territory of his enemy, Yuki Mitsutomo. Naturally, Mitsutomo prepared his troops to prevent him from passing.
In the end, Osaki Akimochi was surrounded by the Yuki army at Ogoshi in Tamura-no-sho, Mutsu (Tamura City, Fukushima Prefecture), and committed suicide.
Because Osaki Akimochi had been defeated and killed, the alliance with the Osaki family did not materialize, and Date Masamune was forced to surrender in October. For the time being, the First Date Masamune Rebellion ended with this.