Columbia subject headings:
Harvard subject headings:
Basil I, Emperor of the East, approximately 812-886.
Byzantine Empire--Foreign relations.
Byzantine Empire--History--Basil I, 867-886.
Princeton subject headings:
Basil I, Emperor of the East, approximately 812-886.
Byzantine Empire--Foreign relations--527-1081.
Byzantine Empire--History--Basil I, 867-886.