I've gotten far enough with the sewing of my savanion to be able to do a little experimenting with draping and wrapping (though no photos, yet). The process has caused me to think about savanions in general.
One of my thoughts was "Why hadn't I heard of, or seen pictures of, such a design before?"
Then it occurred to me that maybe I have seen such a design before.
Look here at this woman in reconstructed Byzantine costume, wearing a savanion. Now consider Rogier van der Weyden's famous painting of Mary Magdalene. It's dated about 1450 C.E.--15th century. She is wearing a few transparent wisps, perhaps of silk, and a thick roll of white cloth about her head. Look familiar? How about these depictions of Irish women in the 16th century?
The savanion was popular during the Middle Byzantine period--at least inside the Byzantine Empire. But what about after that? Is it crazy to speculate that the style might have become known in western Europe because visitors from Byzantium wore it?
That may be why Mary Magdalene is depicting as wearing a version of it. She is often depicted in clothing that is exotic, or odd, or foreign. (So are the Irish, for that matter.)
So maybe the odd wrapped headdresses of Mary and the 16th century Irish women are survivals, or perhaps more precisely, descendants, of the savanion. Maybe someday I'll do some research to try to find out.