Royals Kate Middleton and Prince William Wish Prince Harry a Happy Birthday with Poignant Photo The Duke and Duchess of Cambridge sent birthday cheers to Prince Harry via their social media on Tuesday By Simon Perry Published on September 15, 2020 09:28 AM Share Tweet Pin Email Kate Middleton and Prince William are sending birthday cheers to Prince Harry with a throwback picture shared on social media on Tuesday. As Harry turns 36 more than 5,000 miles away in Santa Barbara, California, they wrote, “Wishing a very happy birthday to Prince Harry today!” The picture they chose to mark the occasion captured a fun day in February 2017 when the trio promoted their Heads Together initiative with a race in London. Showing Harry sprinting ahead of his royal relatives, the event was part of a relay race with other supporters of the mental health campaign. Harry is having “some birthday celebrations quietly with the family” in Santa Barbara, a source close to the Duke of Sussex says. He is expected to catch up with his family, including his father Prince Charles, and brother William, 38, by phone or video chat. Prince Harry, Kate Middleton and Prince William. Chris Jackson/Getty Meghan Markle and Prince Harry Have a Zoom Call Crasher at Home: Archie Makes 'Impromptu Cameos' It is a poignant birthday for Harry as he now is the same age his mother Princess Diana was when she died following a car crash in Paris in 1997. Harry was just 12 at the time. The joyful photo William and Kate selected was from happier times when the trio set up their successful mental health campaign and worked in tandem on the initiative for a few years. More recently, their relationship has been strained and distant as rifts between the princes grew and eventually Harry exited the working royal family with wife Meghan Markle and their 1-year-old son Archie to start a new life in the U.S. earlier this year. Meghan Markle and Prince Harry Will Spend Next Few Months ‘Focusing on Their Family’ Prince Charles also took to social media to share birthday wishes to his son, calling him by his royal title, The Duke of Sussex, and featuring a photo of Harry alongside his father at his first Invictus Games six years ago and another smiling portrait. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! The main royal family social media account also added a charming picture of Harry chatting with his grandmother Queen Elizabeth at an official reception at Buckingham Palace.