Mortimer has done what is almost impossible today: a truly well researched and engaging biography with the blood still pumping madly in the body. His manner of writing is elegant and never academic; he "sees" the whole tempestuous era and the man with a refined eye - this author has vision. My one minute complaint is that the author is overly harsh, in my opinion, about the "treason" of Roger Mortimer - honestly, considering the bizarre treatment that Queen Isabella, from the age of 12 onward, suffered from her husband and what the country itself had to endure with a man who clearly preferred to be doing anything but ruling, guiding, shepherding his country and people, as the anointed king, I wonder that historians haven't recognized that the greatest treason was Edward II against his own heritage, people and government. I was particularly horrifed to read of the brutal betrayal and execution of Llewelyn; perhaps the single act that drove Roger Mortimer to break with Edward II?
As for the likelihood that Edward II survived I would agree with the author's hypothesis, that in order to preserve his own life and that of the Queen, as Edward III came to age, it was better to keep Edward II alive, somewhere, as a hedge against retribution. Had Mortimer died in the Tower, or in exile, and never deposed Edward II one has to wonder if Edward III would have ever had the reign he had: a young man with his whole life in front of him. Had Edward II stayed on the throne and if he lived at least as long as his father, Edward I, then "our" Edward III would have been middle aged, at best, when he ascended the crown. Or would he have been an embittered heir, not married to Philippa of Hainault, embarassed by his father's misgovernment,a son driven to work against his own father, as did Richard I with his father, Henry II?
Perhaps Mortimer acted out of self-preservation but he also created an example of what it takes to be an efficient and resolute king - the tragedy of Roger Mortimer is that he wasn't - directly - of the blood royal; he certainly had everything else it would have taken to be an incredibly competent, conscientious and dutiful king.
By the way, the heirs of Roger Mortimer, who was the first Earl of March, would in 7 generations, barely a 130 years later, become king, and in name - by also deposing an anointed king, and by conquest, and finally having that same king (Henry VI) put to death to maintain the throne - that king was Edward IV. Mortimer's almost bloodless coup, in contrast to his future heir's conquest of the throne, is a study in stunning strategic vision.
The author has my highest respect - I can't imagine a finer example of what biography is meant to achieve; it is in another league altogether from the "royal" biographers like Weir. I can only hope that someday Ian Mortimer will undertake to write about another mishandled subject of history: Richard III, in many ways Richard parallels his Mortimer forebear, a masterful coup with minimum blood and revenge and a likely "murder" he also did not commit but will probably never be able to shake from his reputation either.