What I knew about WWI was accumulated from films, books, documentaries, TV series, etc. I was pretty hazy on some aspects, and guessed that some of what I "knew" was either downright wrong or out-of-date, so I decided to look for a book to educate me. I searched reviews looking for something relatively short, based on modern analysis but accessible, to explain how the war came about, the main events in the war, and the fall-out. This book succeeds on all fronts.
The body of the book is just 187 pages in my copy, and it has to cover a lot in that space. The pre-war history starts with the Franco-Prussian war in 1870/1, and fair gallops through to the summer of 1914. Yet still does a good job of explaining that no war of this size can be considered alone. The narrative of the war is as shocking as I expected. The sheer numbers slaughtered, at times in just one or two days, is horrifying. The image of lambs led to slaughter by incompetent leaders is largely debunked. The one problem I had here is that when we first meet people, their role is explained, but subsequently they're just named. There are so many of them -- some of whose roles changed as they were promoted or demoted -- that I couldn't keep track. When they were involved in major events, brief footnotes would have helped me keep up.
After the major description of the war itself, the book ends with an excellent analysis of both of the tail-end of the war, but also of how it has subsequently shaped history. This definitely changed my understanding of geopolitics -- some things I'd thought were down to WWII are more strongly explained by WWI, for example the carving up of the Middle East.
If you want to understand WWI, I can recommend this book. I'd give it 9/10, but will give it 4 / 5, though only just. Now I want to find the equivalent book for WWII.