Yet what does being "Dragonborn" mean for the various individuals who stole the throne? When the Empress Kintyra II Septim was slain and replaced on the throne by the usurper Uriel Mantiarco, surely the dragonfires were still lit? Kintyra was said to be the last of purely Septim blood, so how could a usurper claim the same protection?
What *is* pure Septim blood, anyway? They're all descended through Tiber's brother, and Uriel Mantiarco, along with his uncles Cephoros and Magnus, were of a separate branch of Kintyra's family--did something not get passed on? And even if it didn't, the dragonfires were clearly still lit during the rule of Katariah and her baseborn son--much less the splinter family of Septims that has since ruled.
There's obviously something special about the Septims, and it probably has to do with Talos--but I'm not sure what.
If I may, a Dragonborn isn't so much the Septim bloodline, as the Cyrodiil bloodline
1. Alessia is that bloodline; the bloodline is Cyrodiil
2. When a Dragonborn is established, they rule from the divine seat of Cyrodiil - the Seat of Sundered Kings
3. Alessia gave birth to Remanada, aka Reman
Cyrodiil, her first Dagonborn
4. Reman was her first, thus Reman established the tradition of the Dragonfires ceremony
5. After Alessia's bloodline was again erased
6, Hjalti reforged it. He ruled from the divine seat as Tiber Septim
8, an heir of Alessia, in the tradition of Reman - yet more fulfilled, because Talos is the completion of a progressive, edification, or mantling
9, of Shezarr. Shezarr was the Missing God whom Alessia named 'freedom;' freedom is catalyst of the Enantiomorph, which Talos was
10.
1 [The Amulet] is the Symbol of the Empire and later taken as the symbol of the Septim line.2 On behalf of the suffering human races, St. Alessia, the first in the line of Cyrodiils...
Thus does Alessia become the first gem in the Cyrodilic Amulet of Kings.3 [N]one dared obstruct Sed-Yenna when she climbed the steps of White-Gold Tower to place the babe Reman on his Throne ; http://www.imperial-library.info/pge3/cyrodiil.shtml
4 [Hrol] spoke to her, saying, I love you sweet Aless... AND HROL DID LOVE UNTO A HILLOCK ...
[A]nd at its peak [Sed-Yenna] saw what it had yielded, an infant she named Reman, which is "Light of Man."5 [Reman] instituted the rites of becoming Emperor, which included the ritual geas to the Amulet of Kings, a soulgem of immense power.6 [S]o shall I run until you learn my pain, which renders you and all this land dead. ...
And in the days of interregnum, the Chim-el Adabal was lost again amid the petty wars of gone-heathen kings. ;
Theologians ascribe the long centuries of political and economic turmoil following the collapse of the Reman dynasty to the loss of the Amulet of Kings, and associate the renaissance of the Cyrodilic empire in the Third Era with Tiber Septim's recovery of the Amulet from Reman III's tomb.7 After their victory, the Nords called Hjalti Talos, or Stormcrown. ... Zurin Arctus, the Grand Battlemage (not the Underking), then crowns Hjalti as Tiber Septim, new Emperor of All Cyrodiil. ;
Talos, anon Stormcrown, the glorious yet-emperor Tiber Septim ;
Tiber Septim (Talos, the Dragonborn): Heir to the Seat of Sundered Kings, Tiber Septim is the most important hero-god of Mankind.8 [Talos'] presence fortifies the Wheel of the Convention, and binds our souls to this plane. ;
Lorkhan is the Spirit of Nirn, the god of all mortals. ;
In the end, [Shezarr] had become “the spirit behind all human undertaking.” Even though this was merely a thinly-disguised, water-downed version of Shor.Edit:
9 Tiber Septim: "The Stormcrown manted by way of the fourth: the steps of the dead. Mantling and incarnation are separate roads; do not mistake this. The latter is built from the cobbles of drawn-bone destiny. The former: walk like them until they must walk like you. This is the death children bring as the Sons of Hora." ;
Lorkhan is the Spirit of Nirn, the god of all mortals. ;
Shezarr was the spirit behind all human undertaking... ;
Once there were Eight Divines. Then Tiber Septim became Talos and the Eight became Nine. I follow the old way, of honoring the Eight while also giving due to Talos, the One who ascended.10 Nirn (Female/Land/Freedom catalyst for birth-death of enantiomorph) ;
[A]nd she said: "And this thing I have thought of, I have named it, and I call it freedom. Which I think is just another word for Shezarr Who Goes Missing... ;
Shezarr (God of Man): Cyrodilic version of Lorkhan... ;
The second to see the Brass God was the Enantiomorph. You may know them individually as Zurin Arctus and Talos. The Oversoul was known to the world as Tiber Septim