To stop your foot slipping through the stirrup and you being dragged if you fall off. I knew from the hour a week at the riding school when I was a kid, as your footwear was policed for safety reasons and no plimsoles permitted as no heel.
I remember Dusty Fog - don't think I could read it now.
Chopines evolved from pattens, which were strap on thick wooden soles for street wear to lift your nice shoes and skirt hem above the literal sh*t in the street. Though Queen Henrietta Maria (Charles 1 Queen) was known for wearing high rise shoes at all times as she was on the short side.
Older high heeled shoes - 18th century - were worn by gentlemen as much as ladies and there was no reinforcement of the arch especially with metal as there is on modern shoes, so if you strode along heel-toe, you snapped your expensive shoe. A careful somewhat mincing toe first gait was preferred. Also you had to move like a dancer as that showed your genteel status as well. "Point those toes children" floats back into my mind.
Went round a stately home recently and a design of chair was pointed out by the guide, which had big gaps in the back - to allow gentleman to whoosh the tails of their coat through it, so they hung nicely and didn't get creased.
And wandering further off topic - documentary on Handel's Messiah last year, the first performance was a serious sell-out, so to provide plenty of seating and space, gentlemen were asked to not wear swords and ladies not to wear the large hoop supported skirts.
