The excitement that has been building around the upcoming nuptials of Prince William and Kate certainly rivals the hoopla that preceded the wedding of William's parents, Charles and Diana, nearly three decades ago. While that union proved to be a spectacular fiasco, only time will tell how this young couple will fare as husband and wife. On the one hand, they've had plenty of time to get to know one another, which bodes well for their happiness. Yet on the other hand, he's royal. And that comes with its own set of complications. Perhaps some hint of what's to come can be gleaned from the marriages of some of William's ancestors--all detailed in my new collection of royal stories, Behind the Palace Doors: Five Centuries of Sex, Adventure, Vice, Treachery, and Folly from Royal Britain.