An excellent book but absolutely not for everyone. Baxter maintains the same writing style and prose that Wells utilized in the first book and picks up a mere thirteen years from the original Martian invasion - which based on a general consensus was most likely set on or around 1907. However, if you've never read the original book this is absolutely not going to make sense - especially if you've only seen the film adaptations. Not only for the writing style but also because of how much this book requires having read the original to make sense - Baxter even goes so far as to continue to use the same science that was prevalent when Wells first wrote the book, the rapidly cooling sun, Martian canals and Venus as a wet jungle world.
Even though the book starts in 1920 it does not follow the same path as ours after England got exsanguinated. England is now a largely totalitarian/fascist society, the Schlieffen War in Europe has left Germany in control of the west but bogged down in an ongoing war with Russia.
With each opposition the world, and especially England, watches for the tell-tale firing of the launchers on Mars - as the original invasion was a mere scouting party and the main force is inevitable.