It’s the dress that launched a million knockoffs, but we’d already seen it.

Kate Middleton walked down the aisle in an Alexander McQueen creation strikingly similar to the gown Grace Kelly wore in 1956, when she wed Prince Rainier of Monaco. Grace’s dress, with its lace sleeves and voluminous skirt, is the most copied wedding gown in history.

The dress isn’t all Kate and Grace share. Kate might as well be an American princess. Like the Kelly clan, the self-made Middletons would never be “high society.” Enter the daughters: poised and beautiful commoners, and neither fashionable.

There. I said it. Grace Kelly, my style icon, wasn’t particularly fashion-forward. Her clothes were boring for 1950s Hollywood. She wore white kid gloves and skirts better suited for librarians than ingenues, but, like Kate, she glowed in any garment.

London’s Victoria and Albert Museum recently hosted an exhibit showcasing Grace’s bland pre-princess attire — dresses sewn from Simplicity patterns, a worn Kelly bag. Even after Grace moved on to couture, she outshone the clothes. As Grace did, Kate will grow into her new wardrobe, and she’ll stay the star. Icons always do.