Seeking Historical Fiction Suggestions à la Downton Abbey

I need your help fellow book bloggers!  I've recently become addicted to the wonderful Downton Abbey and am now interested in reading some historical fiction set in Edwardian England, although the late-Victorian era would also be okay.   I'm particularly interested in any books that feature aristocratic families, like Downton's Granthams, and their stately homes.   Since I've not read widely on this period, I'm looking for recommendations.   The only novel suggested to me to date is Daisy Goodwin's The American Heiress.  

Does anyone have any recommendations?