Board Thread:Lore Discussion/@comment-108.253.68.177-20131021030335/@comment-218.186.253.91-20131024091347

HoK never died, he is sheo, with his soul and memories. Nerevarine might still be alive. None of them had dragon souls (or they will be Dovahkiin as well), so the dragonborn is probably just an unlucky dragon soul stuck in a mortal body (not his own). It is debatable for the first two games, though.

The setting of all of the people starting as prisoners is because they want to have a generic, fresh start type of thing. Lorewise, it is coincidence, but gameplay wise, it's probably a Bethesda cliche.

Not to attack any arguments or speculations, just an opinion