Prince George has been photographed walking with the help of his mother, the Duchess of Cambridge.
His tentative steps were captured on Sunday as princes William and Harry lined up on opposing sides in the Jerudong Trophy at Cirencester Park Polo Club.
It is believed to be the first time the baby prince has been seen taking to two feet in public.
George - who is third in line to the throne - will turn one next month.
He was also seen playing football on the sidelines of the charity polo match.
It was an "impromptu family day out", Clarence House said.