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.

It’s a milestone birthday for Duchess Sophie, who officially rang in the special day on January 20 with a little more pomp and circumstance than usual, courtesy of an official new portrait and plans for a major birthday celebration at their Berkshire home Bagshot Park.

The duchess is set to celebrate the milestone at home with the Duke of Edinburgh on Monday at her Bagshot Park home.

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, Duchess of Edinburgh released a trio of stunning portraits to commemorate her 60th birthday that seemingly included a subtle sartorial nod to her grand new title. See the photos, here.

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.

Photographer Christina Ebenezer also shared her favorite part of the photo shoot Sophie, the Duchess of Edinburgh is starring in a new portrait for her 60th birthday, and the photographer behind the camera is sharing an unseen snap from the photo session.