On Wednesday, Kensington Royal led a stream of posts dedicated to the well-lived royal, with Prince William and Duchess Catherine sharing two candid snaps of themselves with Philip over the years.
"Wishing a very happy 99th Birthday to The Duke of Edinburgh!" Wills and Kate captioned.
As for Philip's son and future King Prince Charles and his wife Camilla, the pair also used their widely followed Instagram platform to wish the Duke a happy day.
In another two images, Charles is seen with his father - the first when he was just a young boy, and the second more recently, snapped when the pair broke into fits of laughter.
"Wishing The Duke of Edinburgh a very happy 99th birthday," Clarence House captioned the pics.
Princess Eugenie also shared a special post for her grandfather, with an official image from her wedding day in 2018, which featured herself, her husband Jack Brooksbank, Princess Eugenie and the sisters' two grandparents, Philip and Queen Elizabeth.
Eugenie referenced the difference in celebrating a birthday in lockdown this year, writing: "A very Happy 99th Birthday to HRH The Duke of Edinburgh.
"Grandpa, we wish you a special day… and may all grandparents celebrating birthdays in lockdown have a wonderful time."
And possibly the most important tribute of all came from Buckingham Palace itself, the official Royal Family account, which shared several snaps of Philip throughout his years.
"Wishing The Duke of Edinburgh a very happy birthday!" The Palace wrote.
"His Royal Highness turns 99 today and will spend the day with The Queen at Windsor," the message stated.
Outside of Instagram, it's understood Prince Harry and Duchess Meghan, who recently moved to Los Angeles, also shared birthday wishes with the Prince via FaceTime.
Royal reporter Carolyn Durand, who is a writer for Oprah Magazine, shared some more details on Twitter.
"A Source close to the #DukeandDuchessofSussex confirm that #PrinceHarry and Meghan with Archie will speak to The Duke of Edinburgh #PrincePhilip today to wish him a happy 99th birthday," Carolyn wrote.
With so many birthday wishes, we're fairly sure Philip was definitely feeling very loved on his special birthday.