After his death, although his first son Mitsunari, who also standing by the East squad with him, succeeded to the family head, his territories were segmented among the four children, and as a result, they were degraded to hatamoto (direct retainers of the bakufu [Japanese feudal government headed by a shogun) of less than 10,000-koku (a stipend of 1,803.9 cubic meters crop yields) class, and hereto, the Seki Domain was abolished.
死後、家督は自分と共に東軍に与した長男の光成が継いだが、所領を４人の子供たちに分地、それぞれ一万石以下の旗本となり、ここに関藩は廃藩となったのである。