| His personal diary (the "Ietada Diary"), has become an important and valuable historical source material to know about the life during the Sengoku Period, as well as the lives of many powerful feudal lords. |
彼の記した日記（『家忠日記』）は、戦国武将の生活や当時の有力大名を知る上で貴重な史料となっている。 |