"Guenevere, Queen of the Summer Country" is a novel by Rosalind Miles, based on Arthurian legend. It chronicles the life of Queen Guinevere (also often written in Modern English as Guenevere or Guenever, as in this case) from her perspective, from childhood to the blossoming of her relationship with Lancelot.
Guenevere is the original version of the much overused Jennifer. I think it's a beautiful name that should be considered by parents who like Jennifer, but realize it's become so common it's a cliche. Maybe they're put off by the fact that Queen Guenevere was unfaithful to King Arthur, though.