Columbia subject headings:
Harvard subject headings:
Holy Roman Empire--History--1517-1648.
Holy Roman Empire--Relations--Spain.
Philip II, King of Spain, 1527-1598.
Social networks--Holy Roman Empire--History--16th century.
Social networks--Spain--History--16th century.
Spain--Relations--Holy Roman Empire.
Princeton subject headings:
Holy Roman Empire--History--1517-1648.
Holy Roman Empire--Relations--Spain.
Philip II, King of Spain, 1527-1598.
Social networks--Holy Roman Empire--History--16th century.
Social networks--Spain--History--16th century.
Spain--Relations--Holy Roman Empire.