The London Lounge

I'd like to know the historical reason for not fastening the bottom button on SB jacket (I know the supposed reason on a waistcoat, is it the same?), and I'm also curious as to when the stigma about this developed... Cary Grant, for instance, is often caught with a fully buttoned jacket.
The Duke of Windsor seems to have had many jackets designed to be buttoned at the bottom; some two button, each either side of the waist, others similar with relatively high button stance and very open quarters (see pics in 'LL tweed operation windsor" thread, though that could be a very low fastening single button coat I suppose, can't tell), and that often reproduced example of his with a roll over the top button and a closure on the lower.

Have any of you had jackets like these? Would you consider it?

According to Hardy Amies's superb "The Englishman's Suit," the modern suit coat derives from country clothes which were meant to be worn on horseback. Hence, the bottom button would not button, and the front quarters of the coat would fall to either side.

Additionally, the modern coat is cut so that there is a cutaway effect at the bottom button and below so that buttoning the bottom will scrunch-up the coat.

Furthermore, leaving the button undone is part of the country origins of the suit in that such exhibits a bit of nonchalance.

thanks for that. I am really interested in opinions on those SB jackets (as mentioned above) which appear to be designed to be buttoned also, or only, at the bottom; how common they were, and whether anyone here would consider them as appropriate in our era.
I remember a great thread about Gabriele d'Annunzio's clothes, that you may search for... in it was a picture of a very interesting jacket with three buttons very close together; how do you suppose that jacket was closed? On all, or two, or one button? (I'd guess two).