Princess Charlotte and Prince George can be seen carrying Prince Louis in a new video released today.
The Prince and Princess of Wales posted the behind-the-scenes video just hours after their first birthday tribute to their eldest son.
The video shows the family in Norfolk, where the photograph that was released to mark Prince George's birthday this year was also taken.
During the video, Prince George, Princess Charlotte and Prince Louis hold hands as they walk towards the camera.
Princess Charlotte and Prince George carry Prince Louis in a new video released today.
The video and pictured were taken by John Shinner.
Earlier on Thursday, the Prince and Princess of Wales shared the new photograph on social media, accompanied by the caption: "Happy 12th Birthday to Prince George!"
Prince George's 12th birthday is particularly significant as a longstanding Royal Family rule looks set to come into place.
The future king may now be separated from Prince William when using certain forms of transport.
The Prince and Princess of Wales shared the new photograph on social media, accompanied by the caption
George is second in line to the throne while Prince William is first in the Royal Family's line of succession.
There is a rule in place that limits which royals can travel together in the same plane, with William travelling on a different plane from Charles once he turned 12 in 1994.
Previously, Prince William, Prince George and Princess Charlotte could all travel together, but that may change now that George has turned 12.
The rule is in place to help secure the heirs to the throne and it can be broken with the monarch's permission, but it is discouraged since, in the event of a crash, the future of the monarchy would be immediately unstable.
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|It may be decided that William is the one to fly on his own, and George travels with his mother and siblings.
It may be decided that William is the one to fly on his own, and George travels with his mother and siblings.
Another option is that William travels with either Charlotte or Louis, or both of them, while George travels with Princess Kate.
Three royals have previously died in plane crashes, including Prince Philip's sister, Princess Cecilie in 1937, the late Queen's uncle, Prince George, Duke of Kent in 1942 and her cousin, Prince William of Gloucester in 1972.