Divorced, Beheaded, Died...: The History of Britain's Kings and Queens in Bite-Sized Chunks by Kevin Flude
This is a great book that I picked up in the Manchester airport last year in England, that informs the curious non-Brit (ok, even Brits, too) about the history of Britain's monarchy. What makes it interesting is that it reads as a chronological and well documented history book, but it is not bogged down with so much information that it becomes boring and unreadable. All the interesting tidbits of each King or Queen from the first to the present is included. It also includes a very brief history of Scottish and Welsh monarchy which is definitely not as common of knowledge as England's, but still a mostly interesting read to quickly browse through.