Board Thread:Off Topic/@comment-4118509-20130420234921/@comment-4118509-20130421012232

Dragons originally came from Akavir. Akatosh traveled to Akavir a long time ago and decided that he wanted to have children with the mortal dragons there. His children became immortal dragons, which is what Alduin, Mimulnir, and the other dragons are. I think that mortal dragons still exist on Akavir.