The Duchess of Edinburgh, who married into the Royal Family over 25 years ago, has steadily climbed the royal ranks to become one of the most respected and admired figures in the monarchy today.

Her unwavering support for her husband Prince Edward, dedication to charitable causes, and warm, approachable demeanour have endeared her to both the royals and the public.

As she prepares to celebrate her milestone 60th birthday in January, broadcaster and author Katie Nicholl tells OK!: "Now, more than ever, we're seeing what a vital cog Sophie is in the royal machine.

"People say she is the 'secret weapon' within the monarchy, and I think that's absolutely true, because she's always there at pivotal moments to help steady the ship. She's seen as a very safe pair of hands, which really became evident during the final years of the late Queen's life as she relied more and more on her substitutes."