The Duke of Edinburgh died in April at the age of 99.
The royal family is marking what would have been a major milestone for the late Prince Philip. The Duke of Edinburgh died in April at the age of 99. On Thursday, he would've turned 100.
"Thinking of my Grandpa on what would have been his 100th birthday," Princess Eugenie shared on her personal Instagram account.
Eugenie welcomed her son, August, back in February, giving the newborn the middle name of Philip in her grandfather's honor.
Prince William and Kate Middleton also paid tribute to Philip on social media, sharing photos of Queen Elizabeth II receiving a commemorative rose bush in her late husband's honor.
"Remembering His Royal Highness The Duke of Edinburgh, on what would have been his 100th birthday," the couple shared on their joint Instagram account.
Additionally, Prince Charles shared a touching throwback photo of himself as a young boy holding his father's hand at the airport following a 1951 trip to Malta.
Prior to the special day, Queen Elizabeth received a touching gift from the Royal Horticultural Society -- a newly bred type of flower, which they've named the Duke of Edinburgh Rose. The rose was planted in the East Terrace Garden at Windsor Castle.
For every Duke of Edinburgh Rose sold, a donation will be made to The Duke of Edinburgh's Award Living Legacy Fund.
RELATED CONTENT: