Grand empress dowager

Grand empress dowager (also grand dowager empress or grand empress mother) () was a title given to the grandmother, or a woman from the same generation, of a Chinese, Japanese and Korean emperor in East Asia, or a Vietnamese emperor in Southeast Asia. 
Some grand empress dowagers held regency during the emperor's childhood. Some of the most prominent empress dowagers extended their regencies beyond the time when the emperor was old enough to govern alone. This was seen as a source of political turmoil, according to the traditional views of Chinese historians.