There's a song by Something Corporate about a girl named Konstantine. Cute song, but an unfortunate name. I suppose I'm biased though, because I love my boy's name and he is so strong and
Constantine fits him so nicely.
Anyway, maybe you could familiarize your relatives with the
Roman emperor and saint and long series of royal men named
Constantine. Also the Hellblazer main character,
John Constantine. :)