Sophie, Duchess of Edinburgh turns the milestone age of 60 on Jan. 20. Here, fashion insiders, including designers of some of the royal's favorite brands, reveal the secrets of her style evolution.

In a series of candid photographs by Christina Ebenezer, the Duchess of Edinburgh chose a wardrobe of re-wears that hint at her new era of royal life

Sophie, the Duchess of Edinburgh is marking a milestone birthday! She turned 60 on Jan. 20, and friends and former colleagues have been honoring her contribution to the royal family – amid the release of the duchess' stunning new portrait.

Duchess Sophie has entered a new decade, and she's ready to face it in style. The Duchess of Edinburgh—who turned 60 on Monday, Jan. 20—has certainly tweaked her wardrobe over the years, and multiple designers recently spoke to People about the royal's evolving sense of fashion.