Archie Harrison Mountbatten-Windsor - the son of Meghan Markle and Harry - is already two.
To mark the occasion, the Duke and Duchess of Sussex shared a new image of the toddler on their Archewell non-profit foundation website. The sepia-toned picture shows Archie, photographed from behind, holding a big bouquet of balloons.
Along with the photo, Meghan and Harry also released a statement calling for community support for vaccine equity to end the coronavirus pandemic.
The California-based royals said they could not think of a "more resonant way" to honour Archie's birthday, pointing out that wealthier countries have used 80 per cent of the nearly one billion COVID-19 shots administered so far, and added, "We will not be able to truly recover until everyone, everywhere, has equal access to the vaccine".
The royals invited everyone to contribute "whatever you can" to bring vaccines to the world's most vulnerable because vaccine roll out has not yet effectively started in much of the world, especially developing countries.
The British Royal family, too, shared a photograph of the Duchess and Duke of Sussex holding their newborn at the Windsor Castle, a royal residence in the English county of Berkshire.
Prince Charles and Camilla, the Duchess of Cornwall, Archie's grandparents, also posted a photo and birthday message from their Twitter account. The post showed Prince Charles and Harry looking at the baby Archie.
The Duchess and Duke of Cambridge - Kate Middleton and Prince William - posted an adorable photograph of Archie along with other family members on the official Instagram handle of Kensington Palace. Kate and William have always posted photographs of the family's children on their birthdays. Continuing with the tradition, the Duchess and Duke of Cambridge shared Archie's photo on social media and wish their nephew on his birthday. The caption reads, "Wishing Archie a very happy 2nd birthday today.
The photo was taken during Archie's christening, and it has Kate and William, Prince Charles, Camilla, Meghan's mother Doria and Princess Diana's sisters. Archie was born on May 6, 2019.
The birthday messages come at a time when it's been a difficult few months for Harry and William and numerous reports of tension between the two couples. Things became worse after Meghan and Harry's interview with Oprah Winfrey, where they made several shocking claims about the royal family.
Archie does not have a title yet and has rarely been seen in public. Harry and Meghan announced in February that they were expecting their second child. Harry last visited the UK in April for the funeral of his grandfather. However, Meghan stayed back in California on the advice of her doctor.
