Monaco’s Charlotte Casiraghi is well known as an equestrian and as a committed ambassador for Chanel, but until this week, she has never gotten an opportunity to combine those two roles on a large scale. On Tuesday, Casiraghi opened the French brand’s Spring/Summer haute couture show on the back of a horse, dressed in a black tweed jacket with jeweled buttons from the collection and a flick of dramatic winged eyeliner.