User blog comment:Zippertrain85/The reasons why Serana is not from the First Era./@comment-3217145-20130508162947

Second: As far as I can tell, the Elder Scrolls themselves don't show up in history either before the events of Oblivion. Does that mean they didn't exist?

We know the Elder Scrolls were around before the Oblivion Crisis, and we know the Ancestor Moths were, too. The fact that they don't show up in history just means they don't show up, it doesn't prove that they weren't there. If the Elder Scrolls didn't figure into history enough to mention them (in the lore we have, since that isn't every book ever written, just the ones Bethesda has included until now), then there's no reason the scrolls' readers would show up, either.

Another addition to this. The Temple of the Ancestor Moths is in Cyrodiil near Skyrim, nowhere near the Imperial City or any other Imperial seat of power. This means it's perfectly possible that the cult started on its own long ago and used this temple, then got wrapped up in the Empire later to keep the scrolls safe or something. Serana knowing about them is not suspicious.