Columbia subject headings:
Byzantine Empire--History--Phocas, 602-610.
Chronology, Byzantine.
Phocas, Emperor of the East, -610.
Harvard subject headings:
Byzantine Empire--History--527-1081.
Byzantine Empire--History--Phocas, 602-610.
Chronology, Byzantine.
Phocas, Emperor of the East, -610.
Princeton subject headings:
Byzantine Empire--History--527-1081.
Chronology, Byzantine.
Phocas, Emperor of the East, -610.