Matsudaira Katamori was born in the Yotsuya district of Edo, on February 15, 1836, at the residence of the Takasu Domain[1] He was the seventh son of Matsudaira Yoshitatsu, daimyō of Takasu, born by one of Yoshitatsu's concubines, a woman of the Komori family whose name is believed by some scholars to be Komori Chiyo (she was also known by her Buddhist name, Zenkyō-in.)[2] Katamori, or as he was first known, Keinosuke (銈之丞), had an eventful childhood. Though the Takasu domain was small, it had a high level of prestige due to its status as a branch family of the Tokugawa clan (through the gosanke house of Owari). Furthermore, in the history of the Takasu-Matsudaira line, there were daimyōs who had been adopted from senior branches of the Tokugawa clan, such as Mito.