 On the death of his father in 1699, he became daimyō of Kasama Domain and head of the Honjō clan.Receiving Lower 4h Court Rank at the end of 1701, he was granted an additional 20,000 "koku" of territory in (Bitchu Province), bringing his total revenues to 70,000 "koku".He was transferred to Hamamatsu Domain (Tōtōmi Province) in September 1702.