I am supposedly related to Princess Diana through her cousin, Winston Spencer Churchill, and then Prince Charles through Queen Victoria. I also have several Presidents, a Mayflower ancestor, Jesse James, Susan B. Anthony, Lizzie Borden, a few of the witches from the Salem Witch Trials and their accusers plus a "judge", members of royal families throughout Europe, including a country or two that I don't think exist any more! What is surprising to me is that most of these come through my mother's side of the family, and she didn't know about them. It's probably a good thing she didn't.............. :) I think there's a site called famousancestors.com, but not sure. You can also go to relativefinder.org, which is hosted by familysearch.org. You will need to create an account with familysearch if you don't have one already (its free and you don't have to be an LDS member to use the site), then you can use your familysearch login information to login to relativefinder. If you don't have a tree on familysearch, you'll need to go back at least 3 generations before it'll pick up on anyone that you are related to. Sometimes you have to go even further back.
I hear you. Who would want to pay the taxes! Besides, I hear castles can be very drafty and cold in the Winters. ;) I have a fascination with such buildings. Castle Navarre is still standing, although now it's under Spanish rule. Once upon a time it was its own nation, closely associated with France. To the point King Henry II of Navarre, took the French throne at some point. The family name I'm connected to used to be spelled Xavier, pronounced ZA-vere, anglicized to Sevier (pronounced like the English, severe). At one time or another, they would visit the castle. It was said they were close, if not in fact related, to the king. I discount this end of the family, but rather pick things up with Jean Valentine Xavier, a Huguenot. who fled Navarre to England, after the edict of Nantes was rescinded.