I liked this book because it gives a really good general history about London, and there's a lot of it! It starts with the Roman occupation and goes all the way up to faily recent times. I am a huge Henry VIII and Elizabeth I nerd, so I had that part of history pretty well covered, but I learned quite a bit about Charles I (only English monarch to lose his head) and World Wars I and II, from a Londoner's perspective.
Nothing is really covered in depth, but I would definitely recommend this book as a starting off point to explore historical topics that you may not have been aware of.