Columbia subject headings:
Normans--Italy.
Sicily (Italy)--History--1016-1194.
Harvard subject headings:
Normans--Italy--Sicily--History
Sicily (Italy)--History--1016-1194
William I, King of Sicily, 1120?-1166.
William II, King of Sicily, 1153 or 1154-1189.
Princeton subject headings:
Normans--Italy--Sicily--History.
Sicily (Italy)--History--1016-1194.
William I, King of Sicily, 1120?-1166.
William II, King of Sicily, 1153 or 1154-1189.