The main character is forced to impersonate a noble( by the noble's sister) because said noble ran away to avoid his responsibilities. They end up falling in love. I believe there may be other women involved but I'm not sure since I read this many years ago. There is a word about this novel I remember: Wolffang or Wolfang, which is the name of the army he ends up leading with the identity of the noble. Sorry I can't give you guys more to work with. Thank you all.