In Japan, even though in the Nara and Heian periods, there were cases where an honorary title of Kotaigo or Kotaifujin (title for previous retired emperors' wife) were dedicated only because the person was the real mother of the Emperor of the time, there is no such example since the early stage of Edo period and it has become a practice that the lawful wife of the former Emperor is named the Taigo.
日本では古く奈良時代・平安時代に、当代の生母というだけで皇太后若しくは皇太夫人の尊号を奉られることもあったが、江戸時代初期以来その例はなく、先代の嫡妻をもって太后とするのが慣例になった。