Even though Hidetada's ability in the military affairs was doubtful, he became the successor, for which it is said that Ieyasu regarded Hidetada suitable as a ruler in the 'Maintenance Ages' (Ieyasu read "Joganseiyo," a book written about Taiso, the second Emperor of Tang Dynasty in China and is thought to have naturally read a sentence in it saying 'Starting a reign is less difficult than carrying it through').
そのように軍事面での才能には疑問が持たれる秀忠だが、それでも後継者となったのは家康が秀忠を「守成の時代」の君主に相応しいと考えていたからだと言われている（家康は太宗(唐)の治世について記した『貞観政要』を読んでおり、当然その中の「守成は創業より難し」という一文も読んでいたと思われる）。