Both were commoners up until the day they walked down the aisle to marry their respective princes. Both have been hailed as fashion icons by the press. Both looked absolutely stunning and very much like princesses on their wedding days. But the similarities don't end there.
The intricate lace appliqué bodice and long sleeves of Kate's dress mirror those of the wedding gown of Grace Kelly, when she married Ranier III, Prince of Monaco, in 1956.
Although Kate's silhouette is sleeker compared to the classic '50s ball gown shape of Grace Kelly's, both dresses share a high-waisted, full skirt and long, dramatic train, which each wore with a diamond tiara holding in place a sheer elow-length veil.
These resemblances reveal how very classic Kate's style is, and how timeless Princess Grace's bridal look was.
The only really big difference was how they styled their hair. Kate wore her brunette locks half up half down, while Grace pulled her blonde tresses up into an elegant bun.
