Columbia subject headings:
Catholic Church.
Church history--11th century.
Church renewal--Catholic Church.
Gregory VII, Pope, approximately 1015-1085.
Harvard subject headings:
Church history--11th century.
Church renewal.
Gregory VII, Pope, approximately 1015-1085
Princeton subject headings:
Catholic Church.
Church history--11th century.
Church renewal--Catholic Church.
Gregory VII, Pope, approximately 1015-1085.