I wonder if the Dread Pirate Roberts from The Princess Bride was modeled after Black Beard in some way. Since I don't know yet how Black Beard stopped pirating (I'll wait to look it up after you finish the tale), the only connection so far is his predecessor retired. In the case of the Dread Pirate Roberts, there were three or four or so, I think, maybe more, and they held things together strictly by reputation, without having to do much killing at all, so that's a departure.

So, betting that he actually fell in love with a princess and went back to marry her is probably a bit farfetched, more than him coming to a most unsavory end.

Then, of course, he could of died by drinking too much, or walking the plank when he was drunk, or some other dumb accident. So many ways to meet your end. :)