Technically (although probably not practically if it's ever tested in a court of law) William the Conqueror's 22nd generation great-grand daughter (Queen Elizabeth II) owns all of England. There was a parliamentary response to this question in 2009; "The Crown is the ultimate owner of all land in England and Wales (including the Isles of Scilly): all other owners hold an estate in land. Although there is some land that the Crown has never granted away, most land is held of the Crown as freehold or leasehold."
Supergirl :)