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.

A photograph of the Duchess of Edinburgh smiling has been released by Buckingham Palace to celebrate her upcoming 60th birthday. The photo of Sophie mid-laugh perched on a window seat at her home in Bagshot Park was captured by the London-based photographer Christina Ebenezer earlier this month.

Sophie, the Duchess of Edinburgh is turning 60 in style. The royal—who marked her milestone birthday on Monday, January 20—released a trio of stunning portraits to commemorate the special occasion over the weekend that seemingly included a subtle sartorial nod to her grand new title.

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

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.