A.T. Robertson Commentary Mark 5:9

"And he asked him, What is thy name? And he saith unto him, My name is Legion; for we are many." — Mark 5:9 (ASV)

My name is Legion (Λεγιων ονομα μο). So Lu 8:30, but not Matthew. Latin word (legio). A full Roman legion had 6,826 men. See on Mt 26:53. This may not have been a full legion, for Mr 5:13 notes that the number of hogs was "about two thousand." Of course, a stickler for words might say that each hog had several demons.