User blog comment:Jimeee/Dragonborn DLC trailer released./@comment-5280592-20121108025750/@comment-199.202.104.234-20121108175120

Personnaly, I believe there is not 2 factions. Only 1 and it's the one you join to fight the first dragonborn. The reason of why we fight him is less unknown.

An another thing to mention, the only dragonborn we know is existence other than our character is Tiber Septim... and I'm about to think that this man may be a descendant of Tiber...