Tokugawa Ieshige
Shigemasa was born in Edo Castle as the eldest son of Tokugawa Munetada, founder of the Hitotsubashi-Tokugawa family, one of the "Gosankyō", the three lesser branches of the Tokugawa clan. His mother was a daughter of the "kampaku" Ichijō Kaneka. His childhood name was Ogimaru (於義丸) given by his grandfather, "Shōgun" Tokugawa Yoshimune. In 1747, on the order of his uncle, "Shōgun" Tokugawa Ieshige, he became the adopted son and heir of Matsudaira Munenori of Fukui Domain. He became "daimyō" two years later on Muninori's death. At the time, he was called by his youth name of Matsudaira Kogorō; however, in 1751 he underwent the "genpuku" ceremony and received a character from Tokugawa Ieshige's name to become Matsudaira Shigemasa. In 1755, his court rank was Junior Fourth Rank, Upper Grade and his courtesy title was "Sakon'e-gon-shōjō" and "Echizen-no-kami".