Siege of Otate
1578 CE.
Shown on the map at 37.167°, 138.236°.
The 1578 siege of Otate (御館の乱, Otate no ran) took place following the sudden death of Uesugi Kenshin. Kenshin had requested that the inheritance be split between his nephew, Uesugi Kagekatsu, and his adopted son Uesugi Kagetora. This conflict happened because of neither heirs being born with the Uesugi name. Kagekatsu was the biological son of Nagao Masakage and Kagetora was biological son of Hojo Ujiyasu. Before the situation could escalate into an armed conflict, Takeda Katsuyori acted as the mediator between those two. Therefore, eventually the Uesugi was divided for a military conflict. The Takeda supported Kagekatsu and the Hojo supported Kagetora. Thus, on April 23, 1578— the 17th day of the 3rd month of Tensho 6 on the Japanese lunar calendar— Uesugi Kagekatsu led a force from his castle at Kasugayama to besiege Otate castle . Kagetora tried to return to Odawara but committed seppuku in Samegao Castle, and Kagekatsu claimed the full inheritance.
Text from the Wikipedia article Siege of Otate, licensed CC BY-SA 4.0.