It makes most sense playing as a nord, with the civil war and all. Otherwise siding with ulfric seems silly "yeah outlanders like me shouldnt be welcome here!".. IMO best gaming experience can be only achieved as a nord in this game.

Accoring to http://elderscrolls.wikia.com/wiki/Tiber_Septim he was born in High Rock.

That only applies if your siding with Ulfric, a great deal of players side with The Empire. Thus being a Nord is of no-consequence. Additionally your not required to side with either of them and can instead broker peace between them.

like it was said a bunch of times any race can be dragonborn as Akatosh chooses who gets the title, mainly when one is needed to save the world. also default will probably be a nord as Bethesda will use the race that fits the setting:

T.E.S 3: set in Morrowind, which was at the time home of the Dunmer
T.E.S 4: set in Cyrodiil, home of the Imperials
T.E.S 5: set in Skyrim, home of the Nords

It surely doesn't make any sense to be the Dragonborn playing a flea-riddled cat or a filthy lizard. Dragonborn is a superior species thing, that is, a human thing. Only Nords, Imperials or Bretons are fit to be Dragonborn. Imperials (Cyro-Nordics) are descendants of the Nords anyway.

I like my Dunmer Dragonborn. I just waltz up to Ulfric Stormcloak, who is really racist towards Dunmer (in case you didn't know) and ask if I can join. It's like droping a several ton F-Bomb in the middle of a church on a Sunday, and adding "Jesus Christ" to the end of it.

Similar to how I told an Imperial Captain in Solitude to "Give me the information I need. That's and order." and him then giving it to me.

Even though it's said that "Only Nords can go to train in the way of the Thu'um." That's just because the Nords are all so 'proud' of their race, that they make it so that they are the only ones to do anything they want, while convincing non-Nords to f-off.

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NORDS!!!

Skyrim's Dragonborn also is not related to the Septims.

Offering myself to that daybreak allowed the girdle of grace to contain me. When my voice returned, it spoke with another tongue. After three nights I could speak fire.

Hahaha Yeah..sure not like more Dunmer in Morrowind hated 'Outlanders' or anything..LOL As soon as u get there many of the Dunmer talk about cutting all outlanders throats in their sleep..and it does not end there...Don't get me wrong i like the Darkelves too...but the Nords are less bigoted than most races i have seen so far..and especially less than those.that got put under somebody else's thumb in their own country so invaders can exploit them.... BTW the Nords (in real life nor in the game) had nothing to do with Nazis any more than the fantasy Dunmer do. LOL But hey if any race could be the Nerervarine than if u want to play a Dunmer Dragonborn more power to u. LOL It's your game.