The young Princess appears in her element in the photograph, hair blown askew in the wind on what appears to be a family hike in the Cumbrian mountains.
Her mother has long extolled the virtues of spending time outdoors.
On the Isle of Mull earlier this week, the Princess stressed the need to get children “outdoors as much as they can”, and added: “It’s the small things that are important.”
Third in line to the throne, Princess Charlotte attends the co-educational private Lambrook School near Ascot in Berkshire and loves dancing, especially ballet and tap.
She has a reputation for being feisty compared with her elder brother Prince George and is often caught on camera keeping both of her siblings in check.
She was last seen in public on Christmas Day, when she accompanied her parents and siblings to church on the Sandringham estate.
Charlotte Elizabeth Diana was born in the Lindo Wing of St Mary’s Hospital in Paddington, London, at 8.34am (local time) on May 2, 2015, weighing 3.7kg (8lb 3oz).
She owes her middle names to Queen Elizabeth II and her late grandmother Diana, Princess of Wales – and is said by royal fans to bear a resemblance to both when they were younger.
She also appears to have inherited her father’s beaming smile.
At the same age, he was pictured karting at Buckmore Park “Playscape” in Chatham, Kent, in August 1992.
The Princess of Wales travelled to the Lake District in March to promote the Scouts in her role as joint president.
In the video, filmed on the shores of Lake Windermere, she spoke of her relationship with nature as she continued her return to work while in remission from cancer, saying the outdoors had been “a place to balance” in “a very busy world”.
She revealed that she had found a “very spiritual, very intense” emotional connection to nature, which had brought her peace.
The portrait comes just over a week after video footage of Prince Louis was released as he posed for his own birthday portrait at the family’s home in Norfolk.
The young prince, who turned 7 on April 23, was filmed leaping off a log and pressing his face up against the camera. He suggested to photographer Josh Shinner: “I can jump down from here”, gesturing to a fallen tree.
In the 20-second video montage, Louis occasionally glanced directly at the camera to offer a cheeky smile and, at one point, shrugged his shoulders with a shy grin.
After leaping off the fallen tree trunk, he landed with both feet, using one hand to steady himself on the ground before standing up proudly and smiling for the camera.
The footage was filmed by the Kensington Palace social media team and posted on the Prince and Princess’ social media profiles.
