Prince Harry and Meghan have asked the public to help vaccinate the world against COVID-19 to mark their son Archie's second birthday.
The couple also released a sepia photograph of Archie playing with a bouquet of balloons, but the photo does not show his face.
Only a small number of photographs of Archie have been released since his birth.
The Duke and Duchess of Sussex stepped back from their official royal duties in 2020 and were stripped of their royal patronages by the Queen earlier this year.
But the proud parents kept charity front of mind when celebrating Archie's birthday, asking the public to consider making a $5 donation to Gavi, the Vaccine Alliance.
The charity buys COVID-19 vaccines for poorer countries whose governments cannot afford them.
"If we all show up, with compassion for those we both know and don't know, we can have a profound impact."
Queen, Charles and William send birthday messages
Archie's birthday was also marked by more senior members of the royal family.
"Wishing Archie a very happy 2nd birthday today," his uncle and aunt, Prince William and Catherine, posted on Instagram.
Archie's grandfather, Prince Charles, sent similarly brief tidings on the Clarence House Instagram account: "Happy birthday to Archie, who turns two today".
The Royal Family Instagram account, which posts on behalf of Buckingham Palace and the Queen, said: "Wishing Archie Mountbatten-Windsor a very happy 2nd birthday today".
Each of the senior royal messages used pictures of Archie's christening or the days after he was born, as he now lives in the United States with his parents.
His first birthday was marked with the release of a video showing his mother, Meghan, reading to him.
