Board Thread:Lore Discussion/@comment-85.74.137.231-20130605091958/@comment-3573184-20130814222527

TheGreenSabre wrote: All I know, the blood of a dragon was given to mortals started with Miraak. Then the gift was given to Alessia. After the war that divided Cyrodiil the true dragonblood lineage was lost and was given to many people in all the races of Tamriel, these people being distant relatives of the late Tiber Septim. After the end of the great civil war the Reman Cyrodiil was given the Amulet of Kings and chosen to be the true ruler of the Tamriel. The Last Dragonborn could be related to any of these legends. Remna came before Tiber, not after.

And there is no reason to assume The dragonborn is related to any of them.