Princess Anne quietly goes about her business, supporting hundreds of patronages and trekking up and down the country and across the world. She's regularly undertaken more engagements in a year than any other royal and yet so much of what the Princess Royal does doesn't end up splashed across the front pages. Not only that, but she detailed what she sees as "one of her biggest successes" as Princess Royal. (Image credit: Photo by Mark Cuthbert/UK Press via Getty Images)The Princess Royal: From Princess Mary to Princess Anne by Helen Cathcart | £11.99/$16.56 at Amazon This fascinating biography focuses on the role of Princess Royal throughout history, including Princess Anne who currently holds this regal title. "One of her biggest successes is that she's never tried to overshadow Charles," Katie said.