The royal trio got their sporting gear on, each wearing an official Team GB Adidas polo shirt for the occasion.
Ever the fashionista, Kate Middleton styled hers up, adding zingy electric blue jeans, and a pair of her favourite summer wedges.
As official London 2012 Ambassadors, the Duke and Duchess of Cambridge and Prince Harry each nominated a person from one of their charities to carry the iconic torch up to Buckingham Palace.
As patron of Mountain Rescue England and Wales, Prince William chose mountain rescuer John Hulse from Ogwen Valley, while Kate Middleton nominated Scout volunteer Jon Sayer, and Harry chose MapAction worker Wai-Ming Lee.
Speaking of his experience, Kate's nominee Jon Sayer told the Mirror: 'It was an unbelievable honour - a day I won’t forget for a long time.
'I got to meet Kate afterwards and we spoke at great length about what we do with our Scouts. She does exactly the same activities on a weekly basis as we do. She said she was loving it.
'We spoke about the flame and I said "thank you for nominating me" and she said "I didn’t put you here, you put yourself here".'
Earlier in the day, Prince William, Kate Middleton and Prince Harry launched a sports project at Bacon's College in Rotherhithe, with Kate arriving in a £35 Hobbs dress.
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