When his father Munetada died, Munehide was an infant and his uncle Muneakira MATSUDAIRA inherited the Miyazu Domain after which Muneakira inherited it.
父・宗允死去後、宗秀は幼少だったため、叔父の松平宗発を挟んで、天保11年（1840年）に宮津藩を相続した。