Six years ago, Rose Hanbury took up residence in Houghton Hall, the sweeping 18th-century Norfolk estate built by Britain’s first prime minister, Sir Robert Walpole, and now owned by her husband, David Rocksavage, the 7th Marquess of Cholmondeley and Lord Great Chamberlain. She felt right at home. “Most of the house is pretty perfect as it is,” Hanbury, 32, offers diplomatically of the stately William Kent interiors. “I don’t feel the need to put my mark on it.” Nonetheless, her personality comes through in the private quarters—Houghton Hall is open to the public part of the year, not unlike a modern-day Downton Abbey—to which Hanbury has added Moroccan tiles and splashes of vibrant color. And it’s not the only way in which Hanbury—who grew up in Devon, in Wembury House, the scene of many a glamorous society bash—has injected the current into the historical. She has also been instrumental in bringing contemporary art to Houghton—most recently, a spectacular James Turrell installation. “I am not someone who likes to be held down by conventions. I’m far happier walking around the house in a floaty Victorian nightgown or a caftan and bare feet than in a cocktail dress and high heels.” Hanbury, pregnant with her third child, in the Yellow Room of her home in Norfolk, England, wears a Salvatore Ferragamo dress; her own jewelry.