The true story of the heroine of Anya Seton's classic novel of historical fiction, Katherine. Katherine Swynford was the lover and eventual wife of John of Gaunt, Duke of Lancaster. Through her children with John of Gaunt, she is the ancestress of many kings and queens of England. Unfortunately, not much is known of Katherine's life, so Alison Weir's book is necessarily a lot of guesswork. Nevertheless, the book is a good window into medieval English history and particularly the role of noble women in it.