Columbia subject headings:
Papal States--Foreign relations--Spain.
Papal States--History--1417-1605.
Papal States--History--1605-1799.
Spain--Foreign relations--Italy--Papal States.
Harvard subject headings:
Catholic Church--Foreign relations--Spain.
Papal States--Foreign relations--Spain.
Papal States--History--1417-1605.
Papal States--History--1605-1799.
Rome (Italy)--Politics and government--1420-1798.
Spain--Foreign relations--Catholic Church.
Spain--Foreign relations--Italy--Papal States.
Princeton subject headings:
Catholic Church--Foreign relations--Spain.
Spain--Church history--16th century.
Spain--Church history--17th century.
Spain--Foreign relations--Catholic Church.