The Kōriyama Domain (郡山藩) thrived within Yamato Province, with its central hub nestled within Koriyama Castle, situated in Yamatokoriyama City, Nara Prefecture.

[1][2][3] Amidst the tumultuous Sengoku period, Yamato Province found itself fragmented between revered temples, influential shrines, and formidable clans.

Following Hisahide's betrayal and subsequent demise, Tsutsui Junkei, succeeded by his adopted heir Sadatsugu, Toyotomi Hideyoshi's brother Hidenaga, and then Masuda Nagamori, a key figure in the Toyotomi government, rose to prominence, securing control of the domain with 200,000 koku.

However, at the pivotal Battle of Sekigahara in 1600, Nagamori aligned with the Western forces while covertly aiding Tokugawa Ieyasu by divulging Ishida Mitsunari's military maneuvers.

Consequently, despite surviving the conflict, Nagamori faced territorial confiscation, albeit his life was spared, purportedly through the intervention of Kōriki Kiyonaga or, as some speculate, by financial means.

Following the transfer of Tadakuni, Nobuyuki Matsudaira from the Akashi domain of Harima Province assumed control with an allocation of 80,000 koku.

Honda Tadayatsu, the fifth lord, assumed leadership at the tender age of five, yet his domain dwindled to 50,000 koku, and he passed away at six years old in 1723, leaving no heir.

As a prominent feudal domain in the Kinai region, it assumed responsibility for safeguarding the Imperial Palace and undertaking fire prevention initiatives in Kyoto and Nara.

The final lord of the domain, from the Yanagisawa clan, was ennobled as an earl in 1884, securing a peerage title.

In a historical account compiled by Okaya Shigemi, a samurai belonging to the Tatebayashi Domain towards the end of the Edo period, Mizuno Katsunari was bestowed with the epithet "Rinkai Fuki," which translates to "too awesome to be tied down to anyone."

This title reflects the awe-inspiring nature of Mizuno Katsunari's character and his exceptional abilities as a military commander.

Following his death, his body was laid to rest at Kenchu-ji, the temple belonging to the Mizuno clan located in close proximity to Fukuyama Castle.

Despite this, in 1919, Katsunari was honored posthumously with an elevation to the lower third rank of the Imperial Court, recognizing his contributions and legacy.

As the fourth generation head of the Honda clan from the Tadakatsu lineage, he was known for his bravery on the battlefield and earned himself the nicknames "Kinaiki" and "Ouchiki."

This conflict led to the September 6 Incident, and Masakatsu passed away in October 1671, causing a dispute over clan leadership that continued after his death.

Despite being intended to take over the Kōriyama Domain, Masanaga was not allowed to due to his young age, causing internal clanm turmoil.

As the second son of Yorimoto Matsudaira, the daimyo of the Moriyama Domain, Honda Tadakuni came from a lineage of notable figures in Japanese history.

He also played a role in establishing Tenjin Shrine and supported local figures like Banzan Kumazawa.

His nephew Tadanao succeeded him as the clan head, and his tombstone in Yamatokoriyama City is a designated cultural property with his career history engraved by Hayashi Nobutatsu.

Honda Tadanao was appointed Jugoinoge and Etchu no kami on December 18, 1702, and later named the adopted heir of his uncle Tadatsune on October 10, 1707.

Honda Tadanao's final resting place is at the Minobuyama Kuonji Temple in Yamanashi Prefecture, where his memory and contributions are honored.