Brought along by his mother the Duchess of Cambridge, née Kate Middleton, George cheered on dad Prince William – who was playing in a charity game on Father's Day.
Playful George showed off his crawling skills, making a dash across the grass – much to his mum's amusement – and was also seen inquisitively picking up a polo stick.
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The Duke and Duchess of Cambridge and Prince George
During a break in play the youngster reached out for his father's bottle of water, sipping from it while sitting comfortably in Kate's arms.
William, 31, and his brother Prince Harry, 29, were on opposing teams taking part in the Jerudong Trophy match at Cirencester Park Polo Club, helping to raise money for a selection of their chosen charities.
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George, who turns one on 22 July, was dressed in a smart white shirt and pink dungarees while 32-year-old Kate kept her look casual in a white-and-navy striped top, jeans and beige deck shoes.
The Duchess is a fan of wearing the nautical, Breton striped top at sporting events, having previously worn it during her sailing race against Prince William when the couple and their son toured New Zealand and Australia.
The Duchess of Cambridge and Prince George
Princes William and Harry have played in the annual polo match before. Last year, when Kate was heavily pregnant with Prince George, William's appearance at the game raised questions over her due date.
It had been widely believed that Kate was due to give birth on 13 July, but when William confirmed his attendance at the polo match so close to that date royal watchers suggested the couple's baby was actually due later in the month.
In 2013 the sporting event raised money for two charities the Duke and Duchess of Cambridge support, Centrepoint and Child Bereavement UK, as well as Prince Harry's own chosen charity, WellChild.
William, Harry, Kate and George weren't the only British royals enjoying a game of polo on Father's Day. The Queen and the Duke of Edinburgh attended the Cartier Polo Cup, at Guards Polo Club in Windsor Great Park.
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Dressed in an vibrant blue coat and hat, Britain's monarch toured the ground with Prince Philip and chatted to guests. The Queen has a busy week ahead with five appearances at Royal Ascot planned.