Columbia subject headings:
Art patronage--Italy--History--13th century.
Popes--Art patronage--History--13th century.
Harvard subject headings:
Art patronage--Italy--History--13th century.
Popes--Art patronage--History--13th century.
Princeton subject headings:
Architecture, Roman--Italy--Rome.
Art patronage--Italy--Rome--History--To 1500.
Art, Roman--Italy--Rome.
Artists and patrons--Italy--Rome--History--To 1500.
Christian art and symbolism--Italy--Rome--Medieval, 500-1500.
Christianity and art--Catholic Church--History--To 1500.
Popes--Art patronage.
Rome (Italy)--Buildings, structures, etc.