User blog comment:Thedoucheinthenorth/The Civil War - Why it is great/@comment-4692902-20121102005428/@comment-3492791-20121108040004

Bretons were a sub-race created by the crossbreeding of the Aldmer (Ancient ancestors of elves) and the Nede (Ancient ancestors of most humans) in an attempt to create a "superior" race. Thus why Bretons are more magically adept than more humans. The Nords also descended from the Nedes, along with all other humans with the exception of Redguards which descended from the Yokudans. Thus no particular race was "here first".

If you want to get very technical, no human race is native to anything in Tamriel, as it was originally home to the Aldmer, which were the first group to settle there. The Nedes eventually migrated there, historically having a clash with the native Snowelves of modern Skyrim and eventually committing their genocide.

Now in the late second era the Nord's territory did not include The Reach, which had been ruled by the Bretons since at least 1E 1030. Tiber Septim then took the Reach from the Reachmen with the Nord-Breton forces of his alliance with Cuhlecain. Later the Nords populated the Reach and subjugated the Reachmen for their native religion practices, eventually leading to the formation of the Forsworn.

The suppression of the Reachmen's religon and cultrual practices was no more justified than the Thalmor suppressing the right to worship Talos. Since the idea of right and wrong varies from culture to culture, it is oppressing another culture to force the views of your culture on a group of people. Look at the Maya, their entire culture was built around the idea that the highest honor possible was to be murdered by the right people, and they were pretty advance about other crap.