Rob had his shot at the crown when he dated Princess Stéphanie of Monaco, daughter of Grace Kelly and Prince Rainier III back in the '80s. While Rob's fling didn't make it past the days of big hair and acid wash jeans, Jessica's royal relationship with Gian Luca Passi de Preposulo has taken her down the aisle and into the ranks of ancient Italian royalty (however, Italy no longer recognizes descendants of its former royal families as being royal).
Before starting a family with Jason Sudeikis, Olivia was married Tao Ruspoli, son of Italian aristocrat Alessandro Ruspoli.
Even The Royals' Princess Eleanor (Alexandra Park) has veered off the palace grounds and dated a commoner. Before we dive back into another season of regal romances with season four of The Royals, let's check out some of the celebs who've dated (and even married!) royals.