"A slender volume" tends to be a derogatory way to refer to a book, but Andrew Roberts has proved that that need not be the case. Physically, his book is certainly small; if there is a smaller book among the many on the subject of Waterloo, I haven't encountered it. This is so well written, however, that the brevity of the book is no disadvantage. The events are recounted with admirable lucidity, but Roberts still finds space for numerous well-reasoned arguments. He does not set out with an axe to grind, as does Peter Hofschroer (with a degree of justice) and as do numerous French authors, desperately trying to prove that the French actually won the battle. He is properly dismissive of the kind of francophone pseudo-historian who is still unable to accept, one hundred and ninety years after the event, that the French were defeated, or that they deserved to be, but his tone is admirably balanced overall (Hofschroer gets a respectful reference). Roberts never explicitly tries to compare Wellington's generalship with Napoleon's, but does draw attention to the flaws in Napoleon's command on the day: late start, unsubtle tactics, assumption of British inferiority, failure to comprehend the significance of the fact that the Prussians were still very much in play, failure to shift his position, to see the battlefield from another vantage-point. There is an ingenious and actually quite plausible explanation of how the insanely conducted French cavalry charges began. I shan't spoil it here (you'll have to read the book). Admittedly, massed frontal charges were exactly how Napoleon conducted the whole battle, so he may well have ordered them, even if his defenders maintain that that is impossible. Roberts leaves space for some illuminating conclusions about the significance of the victory. Napoleon would almost certainly have been steamrollered by the Russians, even if he had won at Waterloo, but a war won by Russia would have led to a very different Europe in the nineteenth century. I don't think that you can have too many books about this fascinating and dreadful battle. Roberts himself pays tribute to Jac Weller, Ian Fletcher and Mark Adkin and is certainly not seeking to supersede their efforts. As far as modern-day analyses of the battle are concerned, however, you can't go wrong with Adkin's masterpiece and this gem from Andrew Roberts, with Hofschroer's works, perhaps, thrown in for a provocatively different perspective.