Board Thread:Lore Discussion/@comment-124.180.169.237-20140619171130/@comment-17114085-20140621193602

The Skyrim conquests were in the early First Era, during Vrage's reign. Gauldur was an Arch Mage in the early First Era. So its not that much of a stretch. Not to mention that there were Bretons before the Nords discovered them, so Gauldur could have just travelled to Skyrim and joined the College. Either way he is canon since Bethesda personally put them in there.