In the late Heian period when Emperors changed frequently in a short period of time, there were cases that a former imperial wife (Empress) was given the title of Empress dowager when a new Empress came into the palace, and she would be elevated to the title of Grand empress dowager when another new Empress came.
天皇の在位期間が短くなる、平安時代後期には、以前に皇后（中宮）だったものが、のちに新たに皇后が立てられると皇太后と称せられ、さらにまた新たな皇后が立てられると、繰り上がって太皇太后の位を贈られるようになった。