"Bess of Hardwick: Portrait of an Elizabethan Dynast" by David Durrant. There are no shortage of brilliant, brave and bold women from the Tudor and Elizabethan era's, but Bess of Hardwick is certainly among the greatest.
Another engrossing book about two of my favorite subjects; Russia and its last czar. One of my favorite authors, Robert Massie, makes this book so readable. You hardly realize you are absorbing historical facts while thoroughly enjoying a good read.