King Henry VI meets a young lad while in prison and is taken with him; he even predicts that little Henry will "bless a regal throne" (4.6.76). Whoa, there, cowboy: he's not even in the running, right? He doesn't even speak.
But (spoiler!) sure enough, Richmond does become king—Henry VII, that is—and puts an end to the whole Wars of the Roses thing once and for all. We just don't see it until Richard III, where he's known as Richmond.
Is Henry just making educated guesses, or is fate somehow at work here? Do Henry's correct predictions suggest that everything is somehow predetermined by fate? Shakespeare won't give us an answer, but it's worth considering that as much as these characters think they're in control of their own destinies, they generally turn out not to be.