An allusion to Mark 5:8-9 in the King James version of the bible:8 For he said unto him, Come out of the man thou unclean spirit.
9 And he asked him, What is thy name? And he answered, saying, My name is Legion: for we are many.
Legion was a body of infantry in the Roman army, ranging in number from 3,000 to 6,000.
Roman Army Legion