Prince Charles shared a personal photo with his father, taken in Malta in 1951, when he was just two years old, on Clarence House's Instagram page.
The couple took to their official Instagram to write a shoutout in honour of Duke of Edinburgh's 98th birthday.
Kate Middleton and Prince William celebrated Prince Philip's milestone via their Kensington Palace Twitter account writing, "Wishing a very Happy 98th Birthday to His Royal Highness The Duke of Edinburgh!" In this picture His Royal Highness was photographed in 1953, 66 years ago.
In the second snap, a black and white photo from the family archive, Prince Philip can be seen dancing with a young Queen Elizabeth. "#HappyBirthdayHRH The Duke of Edinburgh was born on this day in 1921", the caption read.
He is the longest-serving consort of a reigning British monarch and the oldest ever male member of the British royal family.
Philip retired from his royal duties on 2 August 2017, at the age of 96, having completed 22,219 solo engagements since 1952.
However, he was photographed in May at a wedding and in charge of a carriage at a royal horse show. The Duke and Duchess of Cambridge shared individual shots of themselves laughing with Philip, a pic Philip and the Queen and a photo from the 2016 Trooping of the Colour event.