Board Thread:Lore Discussion/@comment-13655364-20130728043755/@comment-9887604-20130728045634

You can fan-fic it as much as you like, however as it stands there is no credible evidence of any Septim members even of distant blood line remaining. One could imagine that they would have attempted to grab power during the second interregnum, yet there is no mention of them beyond Martin. As far as the empire goes, the Septim bloodline has largely lost its relevance anyway. It was needed to maintain the dragon fires, and those are permanently lit due to the sacrifice of Emperor Martin Septim.