Britain's Duke of Edinburgh wants a low-key birthday this year.

Britain's Duke of Edinburgh

Britain's Duke of Edinburgh

The 94-year-old royal celebrates his birthday on June 10 but rather than mark the occasion publicly, he will instead support his wife, Queen Elizabeth, as they attend the National Service of Thanksgiving to mark her milestone 90th birthday.

A spokesperson for Buckingham Palace said: "While The Duke of Edinburgh will accompany the Queen to the National Service of Thanksgiving at St Paul's Cathedral on Friday 10th June, His Royal Highness's birthday will be marked privately."

Meanwhile, Princess Eugenie previously revealed Prince Philip is the royal family's "rock".

She said: "I think Grandpa is incredible. He is strong and consistent. He's been there all these years, and I think he's the rock - for all of us."

Of the Balmoral estate, she added: "It's the most beautiful place on earth. I think Granny is the most happy there. I think she really, really loves the Highlands.

"Walks, picnics, dogs - a lot of dogs, there's always dogs - and people coming in and out all the time. It's a lovely base for Granny and Grandpa, for us to come and see them up there; where you just have room to breathe and run."