Akizuki Castle dates back to 1203, when the Akizuki clan built Mt. Kosho Castle as their headquarters.
The Akizuki clan ruled the area for 385 years over 16 generations, but was defeated by Toyotomi Hideyoshi (1537-1598), the supreme ruler of the Warring States period, in 1587 and left the area.
At that time, Akizuki Castle was once abandoned, but in the Edo period (1603-1867), Nagaoki Kuroda, who took over Akizuki as his fiefdom, restored the abandoned castle after major renovations in 1624, and made it his residence.
After the Samurai world ended and the Meiji Era came, Akizuki Castle was unfortunately destroyed in 1873, leaving only a small portion of the castle, due to the Japanese government’s decree to abolish castles.