Board Thread:Lore Discussion/@comment-10993011-20140918001226/@comment-9212235-20140922001722

Book of the Dragonborn: Because of this connection with the Emperors, however, the other significance of the Dragonborn has been obscured and largely forgotten by all but scholars and those of us dedicated to the service of the blessed Talos, Who Was Tiber Septim. Very few realize that being Dragonborn is not a simple matter of heredity - being the blessing of Akatosh Himself, it is beyond our understanding exactly how and why it is bestowed. My two cents on the subject is that no dragonborn is passed down through blood. Those who are not born with the gift of Akatosh, such as the LDB, Tiber Septim, and others, instead are granted the gift through ritual. This ritual being the lighting of the Dragon Fires, which mimics Alessia's covenant to Akatosh and granted her the power to be the first Dragonborn. Akatosh then bestows his gift on those who rightly perform the ritual. We see the ritual (or at least I'm speculating it's the ritual) being performed in ESO when the Emperor tried to become Dragonborn then was interupted.