Board Thread:Lore Discussion/@comment-8.42.214.202-20190124163653/@comment-35782287-20190126233325

As explained in the Dragonborn DLC, the first Dragonborn, Miraak's job was to defeat Alduin. He refused and joined them.

The Last Dragonborn does defeat Alduin. Now there's no more need for Dragonborns.

The Septims had Dragonblood because of Alessia's pact with Akatosh, the Dragon God. There were no dragons involved with this. . . with the exception of Tiber Septim, who had Dragonblood from that pact and was a Dragonborn.