[1][2][3] At the start of the Edo period, the area around Akashi was part of the vast holdings of the Ikeda clan of Himeji Domain.
Ogasawara Tadazane, the son-in-law of Matsudaira Nobuyasu received a 100,000 koku portion, which formed Akashi Domain, and he was ordered to construct a castle.
The 8th daimyō, Matsudaira Narikoto, was an adopted heir and was born the 25th son of Shogun Tokugawa Ienari.
However at the start of the Boshin War, as Matsudaira Yoshinori was leading his armies in support of Tokugawa forces at the Battle of Toba-Fushimi, he received word that the Shogun Tokugawa Yoshinobu had abandoned his army and had fled Osaka by ship back to Edo.
His forces were ordered to fight in the Boshin War as part of the rear guard against Himeji Domain and in Echigo Province.