Kate Middleton shines in polka-dot dress at Garter Day ceremony.

Kate Middleton paid tribute to Princess Diana by wearing a black-and-white polka dot midi dress by Alessandra Rich to the Garter Day service at St George's Chapel. The dress is reminiscent of a dress Diana wore to Royal Ascot in 1988. Kate paired the dress with a Philip Treacy headpiece and Jennifer Chamandi heels, both of which were inspired by accessories Diana wore to Ascot. The Italian-born, London-based designer Alessandra Rich has become a go-to for Kate in recent years. The Garter Day service is a 700-year tradition founded by Edward III in 1348 and recognizes contributions of great public service from those honored.