Columbia subject headings:
Byzantine Empire--History--Constantine XI Dragases, 1448-1453.
Byzantine Empire--History--Palaeologi dynasty, 1259-1448.
Byzantine Empire--Relations--Turkey.
Turkey--History--1288-1453.
Turkey--Relations--Byzantine Empire.
Harvard subject headings:
Byzantine Empire--History--Constantine XI Dragases, 1448-1453.
Byzantine Empire--History--Palaeologi dynasty, 1259-1448.
Byzantine Empire--Relations--Turkey.
Turkey--History--1288-1453.
Turkey--Relations--Byzantine Empire.
Princeton subject headings:
Byzantine Empire--Foreign relations--Turkey.
Byzantine Empire--History.
Istanbul (Turkey)--History--Siege, 1453.
Turkey--Foreign relations--Byzantine Empire.