What do you get when you join a member of Monaco royalty with one of the world's most prestigious jewellery companies? A whole lot of glamour, that's what! Charlotte Casiraghi, daughter of Princess Caroline of Hanover, was on deck to assist Cartier with the opening of the El Arte de Cartier exhibition in Madrid last night, doing double duty for the day and night-time events, hosted at the Museum Thyssen Bornemisza. We were (as usual) impressed with Charlotte's classic sense of style, but it was the jaw-droppingly beautiful jewels from Cartier's archives that really held our attention. Over 400 pieces are currently on display, including bespoke creations for the likes of Coco Chanel, Wallis Simpson, Grace Kelly and Elizabeth Taylor. From iconic Cartier leopard cuffs to art deco collars to diamond-encrusted tiaras, you just gotta have a look.