I started with Ian Mortimer's books back with The Greatest Traitor, and so was well familiar with his Edward II faked-death scenario (which I ascribe to). Though the cover does suggest a more light reading or pop-history-mystery kind of book (after 'Time Traveller's' it's not an unwarranted expectation), Ian Mortimer is still a professional historian, and so it was of little surprise to find a book full of more academic-based essays, to reply to all the backlash of his view about Edward II. Welcome, in my humble opinion.
I bloody loved it. I devoured it almost non-stop in fact, and one question after another in my head was answered about the puzzle of Edward II, questions that built up since The Greatest Traitor and the incredible twisted web of secrecy in the Middle Ages. I bought the book primarily for the sections on Edward II (surely history should have remembered him as the Poker King, right?) but found the intrigue of the cover in the sections of royal pretenders and blurry lines of succession just as fascinating, as I knew little about those subjects and how deep they went in the Middle Ages. The poker thing is so astonishingly boring in comparison to the finely woven lines of a secret survival!
I'm inclined to enjoy scholarly texts just as much as popular literature, but if you base your purchase of this volume only on your love of the Time Traveller series, then I highly recommend familiarising yourself with both 'The Greatest Traitor' and 'The Perfect King' first (and even 'The Fears of Henry IV' considering the succession sections), for necessary background on the author's attentions and an ease into the drier aspects of this work. They are balanced and readable factual books, and you might find yourself much more sucked in by the hardcore history of this one afterwards. Plus, Plantagenets. 'Nuff said.