After transferred to Utsunomiya, he strongly felt that the vassal system that had continued from the time in Mikawa does not work any longer, so he carried out reforms in the senior vassal system.
宇都宮への転封後、三河時代からの家臣団制度が機能的でなくなったのを痛感した家昌は、重臣制度改正に着手した。