Hollywood star Sir Ben Kingsley has led tributes to the Prince of Wales as thousands gathered at Buckingham Palace to mark the 40th anniversary of his Prince's Trust.
The Oscar winning actor described Charles as having the unique combination of "enormous compassion, without ego" as Trust beneficiaries, celebrity supporters and staff enjoyed a palace garden party hosted by the heir to the throne.
Among the famous faces were singers Pixie Lott and Paul Young, actresses Dame Joan Collins and Gemma Arterton, BBC presenter Fearne Cotton and former James Bond star Sir Roger Moore.
Kylie Minogue had to cancel her appearance due to ill health, said a Trust spokeswoman.
Sir Ben has been an Ambassador for the Prince's Trust for the past 20 years and as some of the young people who have benefited from the organisation's support and training enjoyed cream teas, he said: "To meet them and hear their now un-interrupted confidence and self worth is so beautiful, having had their lives shattered by illness or poverty or abuse."
He said that 89p of every pound raised was spent on the young people helped but added: "It's not throwing money at the problem, it's throwing intelligence and care and affection, and I think at the centre of it is HRH's (His Royal Highness) profound affection for what he does and the people for whom he does it.
"I think he's a very unique combination of enormous compassion, without ego - it's a very rare combination."
During the garden party Dame Joan and Gemma presented Charles with a portrait of himself created from hundreds of images of people whose lives have been touched by the work of his Trust.
Sir Ben presented Charles with a digital book of memories - a touch screen device containing photos and recollections recorded by young people and supporters of Trust and gathered during a nationwide road show.
The Trust grew out of Charles's concern that too many young people were being excluded from society through a lack of opportunity. In 1976, when he left the Royal Navy, he used the £7,400 he received in severance pay to fund a number of community schemes. These early initiatives were the founding projects of his charity.
Around the country, 21 pilot projects were set up - from a grant given to a 19-year-old woman to run a social centre for the Haggerston Housing Estate in east London, to funds used to hire swimming baths in Cornwall to train young lifeguards.
During the past 40 years it has grown to become Britain's leading youth charity and has reached more than 825,000 young people in total, with three in four achieving a positive outcome - moving into education, employment or training.