The Constant Princess by Philippa Gregory.  Comes the remarkable story of Katherine of Aragon, Princess of Spain, daughter of two great monarchs, and eventual Queen of England when she marries the infamous King Henry VIII. Daughter of Queen Isabella and King Ferdinand of Spain, Katherine has been fated her whole life to marry Prince Arthur of England. When they meet and are married, the match becomes as passionate as it is politically expedient. save England when its old enemies the Scots come over the border and there is no one to stand against them but the new Queen......