During the
Sengoku period, northern Mutsu came under the control of the
Ashina clan, originally retainers of the
Date clan, who had declared their independence during one of the Date clan's numerous
internal conflicts.
Ashina Moriuji (1521–1580) expanded his territory from the Yonezawa basin to the
Aizu and
Nakadōri regions, seizing
Shirakawa Castle and
Nihonmatsu Castle and building Kurokawa Castle (later known as
Aizuwakamatsu Castle as his capital. When he retired and turned power over to his son, Ashina Morioki (1547–1574), he built Mukaihaguroyama Castle as his place of retirement and to strengthen the defenses of the Ashina territories to the south. The defenses of the castle were strengthen by
Ashina Moritaka (1561–1584); however, he proved to be an unpopular ruler and was assassinated in 1584. The Ashina clan was then defeated by
Date Masamune at the
Battle of Suriagehara in 1589. The Date clan was soon relocated from Aizu to
Sendai by order of
Toyotomi Hideyoshi, and the castle came into the hands of
Gamō Ujisato, followed by
Uesugi Kagekatsu. Both used the more conveniently located Aizu-Wakamatsu Castle as their main base, and retained Mukaihaguroyama Castle primarily as a final redoubt in case of war. Following the
Battle of Sekigahara and the establishment of the
Tokugawa shogunate, the
Uesugi clan were relocated to
Yonezawa Domain, and Mukaihaguroyama Castle was allowed to fall into ruin. At present, only some remnants of the earthworks and moats remain. ==See also==