Columbia subject headings:
Harvard subject headings:
Byzantine Empire--History--1081-1453.
Comnenus family.
Emperors--Byzantine Empire--Biography
Pontus--History.
Trebizond Empire--Civilization.
Trebizond Empire--History.
Princeton subject headings:
Byzantine Empire--History--1081-1453.
Comnenus family.
Emperors--Byzantine Empire.
Pontus--History.
Trebizond Empire--Biography.
Trebizond Empire--Civilization.
Trebizond Empire--History.