Hello,
it is a 19. ct. European, probably German, Hunting dagger (deer catcher).
If you follow this link, you will see more examples of the same type.
https://www.google.de/search?q=hirsc...w=1670&bih=921
If you find something of interest, I will translate it for you.
Sometimes they had been used as a side weapon for upper class on the battlefield. Maybe the extremely long bayonets of late 19.ct. are copies of the deer catcher worn in battles.
Roland