Prince William and Kate Middleton lead tributes to Prince Philip on his 99th birthday

The Duke of Edinburgh is currently isolating with the Queen at Windsor Castle

Credit: Ward/

Prince William and Kate Middleton have led tributes to Prince Philip on his 99th birthday.

In a post on their official Instagram account, the couple shared photos of them both with William’s grandfather.

They captioned the post: “Wishing a very happy 99th Birthday to The Duke of Edinburgh!”

Prince Charles also paid tribute to his father via the official Clarence House Instagram account.

The Prince of Wales shared a photo of him smiling with his father at an official engagement, and also included a childhood photo taken on the Isle of Wight back in 1957.

Last night, the royal family released a poignant new photograph of Prince Philip and Queen Elizabeth II, to mark his 99th birthday.

The photo was taken in the quadrangle at Windsor Castle last week, where they have been isolating over the past three months.

According to reports, Windsor Castle staff have been going to extraordinary lengths to protect the Queen and Prince Philip from COVID-19.

According to The Sun, the couple are being looked after by 24 devoted employees, who work on a “three weeks on, three weeks off” basis.

The staff members are split into two groups of 12, who spend two weeks at home and a third week in quarantine during their time off.

Before returning to work, each employee is then tested for Covid-19 and has their temperature taken.

Credit: John Rainford/

This means they can serve the Queen and Prince Philip without needing personal protective equipment.

A source said: “No chances can be taken with the Queen and the Duke’s health, so it’s totally understandable. But the fact this move has been taken indicates there will be no change soon.”

“The Queen will clearly be in lockdown for many months. It’s hard to see when it will be deemed safe for her to venture out again.”