I bet it is not easy to write a quick summary of history's greatest battles: not only one must choose which battles are considered to be the greatest, but also describe the battle itself and the relevant context in 20-30 pages. I wouldn't be surprised to learn that there is a full book dedicated to each of the battles included in this book by Nigel Cawthorne. Partly because of this challenge, I am going to be more forgiving in my review, but I am not going to deny it: I didn't really like this book.
Firstly, I was hoping to read more about the background context rather than the actual description / tactics of battles. I personally would prefer to have less battles covered in this book, but in greater detail, as I felt like there was not much context provided. Also, having maps or some other visual representation would have been helpful.
Secondly, to me it looked like the author, possibly unconsciously, was biased towards choosing battles involving white/European nations. Obviously, WWI and WWII were covered sufficiently, but I was hoping to read more about Asian/African conflicts and battles as well.
Finally, the book had some obvious punctuation and grammar typos which I personally found a bit annoying.