So I'm perusing a draugr-infested barrow in Skyrim, and I happen upon a copy of The Talos Mistake, which I assume would have had to have been written sometime within the past 200 years since the Oblivion Crisis. And I find copies of The Real Barenziah all the time.

The books themselves are probably just an oversight or a quirk of randomization or something, but it got me thinking. How old are these barrows and the draugr within supposed to be?

Do any lore junkies know if there were ever any dates mentioned as to when these barrows were built? While a lot can happen in 200 years, I'm guessing they're supposed to be a lot older than that.

Anywhere from the mid Merethic to the early 1st era, I think. However, they were used as burials up to the http://www.uesp.net/wiki/Skyrim:Ancestral_Worship, which would explain the books. I'm more inclined to just ignore them as a byproduct of procedural generation.