The title refers to two 16th century monarchs, cousins and contemporaries whose lives would profoundly affect each other. Elizabeth I, Queen of England, and Mary, Queen of Scots. Both provoked passionate partisans from their own day to ours; Elizabeth usually named as among the greatest monarchs ever to rule over Great Britain (including by Dunn), and Mary as a romantic figure and purported martyr to her Catholic faith. From what I read of the book, I’d say Dunn is definitely on Elizabeth’s side--but then so am I. So I don’t have any objection to Elizabeth being held up as a model ruler while Mary is made an example of a failed one. I can’t complain of Dunn’s style either on a line-by-line basis. It’s clean and competent and flowing. The book is insightful and obviously well-researched, with extensive notes of sources. For instance, I liked how Dunn noted just what texts the young Elizabeth read that might have influenced her politics--Cicero, Livy--and Plutarch who wrote of the great Egyptian Queen Cleopatra and her fall. So why only two and a half stars? In a word: structure. In her Preface Dunn claimed the book is “not a dual biography” but rather “follows the dynamic interactions” of the two women and is not “chronological.” I soon saw what she meant, and I found her form irksome. Her opening chapter juxtaposes Elizabeth coming to the throne with Mary’s marriage to the heir to the throne of France in 1558. Dunn throughout the book bounces from woman to woman and jumps back and forth chronologically, and the result just doesn’t flow. I found myself wanting to abandon the book and instead reread Lady Antonia Fraser’s Mary, Queen of Scots and try the biography of Elizabeth by Anne Somerset recommended by Dunn in her preface. So that’s what I did--abandoned this “not a dual biography” before reaching the 150 page mark.