Columbia subject headings:
Castles--Italy--History.
Italy--History--16th century.
Italy--History--476-1492.
Harvard subject headings:
Castles--Italy--History.
Italy--History--16th century.
Italy--History--476-1492.
Princeton subject headings:
Castles--Italy--History.
Italy--History--16th century.
Italy--History--476-1492.