To wit, in James Branch Cabell's own words, from his preface to "The Witch Woman", the book which he has "not as yet published."
So, 700 years of human history, as we know it, is, in fact, the Norns second version, a somewhat muddled affair it seems.
And the period ends, in a monstrous act of egotism, in 1879 upon the date of the author's birth.
And so, Cabell has wrapped up his Biography in as neat an alternate-history scenario as you will find in the hardest of hard sci-fi.