The Holy Roman Empress or Empress of the Holy Roman Empire (Kaiserin des Heiligen Römischen Reiches) was the wife or widow of the Holy Roman Emperor. The elective dignity of Holy Roman emperor was restricted to males only, but some empresses, such as Theophanu and Maria Theresa, were de facto rulers of the Empire.
Judith of Bavaria (c. 797-805 – 19 April 843) was the Carolingian empress as the second wife of Louis the Pious. Marriage to Louis marked the beginning of her rise as an influential figure in the Carolingian court. She had two children with Louis, Gisela and Charles the Bald. The birth of her son led to a major dispute over the imperial succession, and tensions between her and Charles' half-brothers from Louis' first marriage. She eventually fell from grace when Charles' wife, Ermentrude of Orléans, rose to power. She was buried in 843 in Tours.
Ermengarde (or Irmingard) of Hesbaye (c. 778 – 3 October 818), probably a member of the Robertian dynasty, was Carolingian empress from 813 and Queen of the Franks from 814 until her death as the wife of the Carolingian emperor Louis the Pious.