I had mis-stated earlier, it is the Stuart Society that drinks to the "King over the water". Anyway, I have a small book here that tells the story of 27 "Pretenders The The English Throne", by Jeremy Potter. There are probably more.
And, of course we can't forget Zsa Zsa's "Hohenzollern" pretender. And did Barbra Hutton not once marry a pretender to some throne?
Lost Aztec & Inca emperors, and even a few Chinese, one living in Hawaii seems to come & go- he claims to be the rightful Machu Emperor.
Cheers,
Robert