[Serialization: The role of the previous nine years and the role of the second third year ①] Why did the Ou War at the end of the Heian period take place...

Also known as the ``Twelve Years' Battle of Oshu,'' this battle was fought in Mutsu and Dewa, present-day Iwate and Akita prefectures, at the end of the Heian period.

Daiwa Consilio2023.11.28