Some of England's grandest country houses are to be found in this prosperous rural county. The Elizabethan Renaissance Kirby Hall, the Jacobean mansion at Apethorpe, the late 17th-century French-inspired Boughton, Hawksmoor's stately Baroque Easton Neston, and the interiors of Althorp provide a fascinating survey of changing taste through the centuries. Complementing them are smaller buildings of great character, supreme among them those of Sir Thomas...