From the immense staff running a lavish Edwardian estate and the lonely maid-of-all-work cooking in a cramped middle-class house to the poor child doing chores in a slightly less poor household, servants were essential to the British way of life. They were hired not only for their skills but also to demonstrate the social standing of their employers--even as they were required to tread softly and blend into the background. More than simply the laboring...