On the death of his father, Sakai Tadatoshi in 1627, Tadakatsu inherited the Kawagoe Domain. He added an additional 20,000 "koku" to the domain's holdings in Musashi Province in 1632 and his court rank was increased to Lower 4th, Junior Grade, with the additional courtesy title of "Jijū" added to his honorifics. In 1634, he was transferred to Obama Domain, whose holdings covered all of Wakasa Province, with additional holdings in Echizen, Ōmi and Awa. This brought his total "kokudaka" to 123,500 "koku".