Columbia subject headings:
Harvard subject headings:
Byzantine Empire--History--Sources.
Church and state--Byzantine Empire--History--Sources.
Church and state--Europe--History--Sources.
Europe--History--Sources.
Secularization--Byzantine Empire--History--Sources.
Secularization--Europe--History--Sources.
Princeton subject headings:
Byzantine Empire--History--Sources.
Church and state--Byzantine Empire--History--Sources.
Church and state--Europe--History--Sources.
Europe--History--Sources.
Secularization--Byzantine Empire--History--Sources.
Secularization--Europe--History--Sources.