We just love this illustration of a Dacian warrior and his horse in armor from Thomas Hope’s Costumes of the Greeks and Romans (1962 edition).
At first glance, though, it kind of looks like they were wearing matching crocheted outfits. I don’t know that such a thing has been done before, but based on the number of images I can find of crocheted chainmail and horses in sweaters, it seems entirely possible.
