Sakanoue no Tamuramaro
Taga Castle was rebuilt after being sacked and burned by the Emishi in 780 AD. From 802 AD, the frontier between Yamato and Emishi territories shifted further north due to the successful campaigns of Sakanoue no Tamuramaro, and with the construction of Isawa Castle, Taga Castle gradually lost importance. It was retained as a center for administrative functions, but most military activities were transferred to various northern strongholds. It was badly damaged by the Jōgan tsunami of 869.