Yesterday evening I was working on the bottom inch of Isabel's plum version of the Audrey Coat and watching a Lucy Worsley documentary on the Regency. I often knit and watch documentaries--they're not so engrossing that I have to catch every single moment, but they're interesting enough to get me through the boring bits (like the bottom half of the coat). Lo and behold, there Lucy appeared in a plum coloured wool coat complete with wide collar, big buttons, and (yes!) a back pleat. To see the coat in action, with its gracefully swinging pleat, go to minute 42:27 and watch Lucy mount the steps of the train.
According to Lucy's blog post from 2013, "My purple coat is in fact my favourite. I wore it in ‘Elegance and Decadence, The Age of the Regency’
and it came from LK Bennett (though had to be extensively cut down at
the tailor’s, because LK Bennett make clothes for goddesses, not gnomes
like me.) You can’t see it in this view [a photo taken from the front], but it has a kind of cocoon
shape with a very clever pleat down the back."
I guess nothing is ever really new in fashion!