It looks a little like a mortising ax but not quite. Most mortising axe's had a straight blade that was centered in the middle of the axe rather than at the top like yours. Also the polls are usually beat up quite a bit, since the axe was made to be struck rather than true chopping.
The metal guard on the handle was usually put there to prevent the handle from breaking in case you missed what you were aiming at. It was usually used on an ax used for splitting.
Mike
