Why do Bretons have a power called Dragonskin? This has been consistent from Morrowind to Skyrim. Is there a lore connection between Bretons and Dragons (I have not been able to find one with a relatively quick search) or is this simply a matter of using the term Dragon as a metaphor for toughness?
Any lore experts have an opinion?

Boring answer: it is just a cliche fantasy label for saying it is a strong protection effect.

Interesting answer: [insert headcanon]

http://www.reddit.com/r/teslore/comments/11tvzj/are_bretons_somehow_inherently_linked_to_dragons/

Edit: Basically, my personal opinion is that the Bretons romanticize dragons. A fascination with dragons came with their Nordic origins, and they have since then forgotten the disgust (in that the dragons are cast as villains in Nordic culture) that came with it.