薩長同盟
During the Boshin War, Nihonmatsu Domain joined the pro-Tokugawa Ōuetsu Reppan Dōmei, and was the site of the Battle of Nihonmatsu as part of the overall Aizu campaign. During the struggle, the castle fell after a single day to the superior firepower of the modernized Satchō Alliance forces of the new Meiji government, during which 337 samurai from Nihonmatsu and 206 samurai from allied domains were killed and much of the castle was destroyed.