The couple, who were married on November 20, 1947, at Westminster Abbey, will celebrate their wedding anniversary at Windsor Castle on Friday.
A new photograph has been released to mark the occasion which shows the Queen and Prince Philip sitting together on a sofa in the Castle’s Oak Room reading a home-made card from the Cambridge children.
The gift from George, Charlotte and Louis features a large number 73 which has been coloured in with stripes and pops out from the front of the card.
The photograph, which was taken by Chris Jackson from Getty Images, also shows a pile of anniversary cards sent by well-wishers.
The Queen is wearing a pale blue double wool crepe dress by Stewart Parvin and a Chrysanthemum Brooch.
The 94-year-old was photographed wearing the brooch, which is made of sapphires and diamonds and set in platinum, during her honeymoon at Broadlands in Hampshire when she was a 21-year-old Princess.
She was also seen wearing it in photographs taken to mark their 60th wedding anniversary in 2007.
The Queen and Duke, who has retired from public duties, are spending the second coronavirus lockdown in England isolating together at Windsor Castle.