Columbia subject headings:
Military art and science--Rome.
Rome--Antiquities.
Rome--History--Empire, 30 B.C.-284 A.D.
Harvard subject headings:
Military art and science--History--To 500
Military art and science--Rome.
Rome--Antiquities.
Rome--Army
Rome--Army.
Rome--History--Empire, 30 B.C.-284 A.D.
Princeton subject headings:
Rome--Antiquities.
Rome--Army.
Rome--History, Military.
Rome--History--Empire, 30 B.C.-284 A.D.