Soon after the birth, he was given the family name Matsudaira and the mallow crest according to the lineage of his older maternal half-brother Motoyasu MATSUDAIRA (who later changed his family name to Tokugawa).
生後、間もなく異父兄の松平元康（後に徳川姓）より、家門に准じて、松平氏の称号並びに葵紋を賜う。