There's a book by of the same name to accompany the series, too, but in case anyone was thinking of buying it, I personally don't recommend it.
I borrowed it from the library and returned it in just a few days. Although it is divided into chapters matching the tv programme, each is filled with a mis-matched jumble of excerpts and paragraphs, some repeating what has been shown on the screen and some with expanded information. The book simply did not 'flow' and I found it a most dissatisfying read.
Sorry, Griff!