Columbia subject headings:
Constance, Empress, consort of Henry VI, Holy Roman Emperor, 1154-1198.
Sicily (Italy)--History--1016-1194--Sources.
Sicily (Italy)--History--1194-1282--Sources.
Harvard subject headings:
Constance, Empress, consort of Henry VI, Emperor of the Holy Roman Empire, 1154-1198.
Constance, Empress, consort of Henry VI, Holy Roman Emperor, 1154-1198
Diplomatics--Italy--Sicily.
Sicily (Italy)--History--1194-1282--Sources.
Princeton subject headings:
Sicily (Italy)--History--1016-1194--Sources.
Sicily (Italy)--History--1194-1282--Sources.