For the first-century Roman, being clean meant a public two-hour soak in baths of various temperatures, a scraping of the body with a miniature rake, and a final application of oil. For the seventeenth-century aristocratic Frenchman, it meant changing his shirt once a day, using perfume to obliterate both his own aroma and everyone else's, but never immersing himself in - horrors! - water. By the early 1900s, an extraordinary idea took hold in North America - that frequent bathing, perhaps even a daily bath, was advisable. Not since the Roman Empire had people been so clean, and standards became even more extreme as the millennium approached. Now we live in a deodorized world where germophobes shake hands with their elbows and where sales of hand sanitizers, wipes and sprays are skyrocketing.

The apparently routine task of taking up soap and water (or not) is Katherine Ashenburg's starting point for a unique exploration of Western culture, which yields surprising insights into our notions of privacy, health, individuality, religion and sexuality.

Ashenburg searches for clean and dirty in plague-ridden streets, medieval steam baths, castles and tenements, and in bathrooms of every description. She reveals the bizarre rescriptions of history's doctors as well as the hygienic peccadilloes of kings, mistresses, monks and ordinary citizens, and guides us through the twists and turns to our own understanding of clean, which is no more rational than the rest. Filled with amusing anecdotes and quotations from the great bathers of history, The Dirt on Clean takes us on a journey that is by turns intriguing, humorous, startling and not always for the squeamish. Ashenburg's tour of history's baths and bathrooms reveals much about our changing and most intimate selves - what we desire, what we ignore, what we fear, and a significant part of who we are.