The prince's closest friends are throwing him a 30th birthday bash in London and have "surprise entertainment" planned, a source tells PEOPLE, noting that contrary to reports, neither Princess Kate nor her onetime party-planning sister, Pippa, are organizing the festivities.
The prince, who turned 30 on Monday, has now reached the age where he has full access to the $16 million left to him by his mother, Princess Diana. And though he has a well-known penchant for, ahem, cutting loose (who can forget this or this?), those who know him best say he has evolved into a thoughtful leader – while still retaining his intense charisma.
"You could parachute him into anywhere, and he is a magnet," a family friend tells PEOPLE. "People want to talk to him and he wants to talk to them and have a laugh. But give him a serious job to do, and there is no chance of him being frivolous."
The prince's passion for helping others has been especially evident in his work with the Invictus Games, a Paralympic-style event for wounded and sick veterans that he founded last year.
"He has charm and charisma," adds Martin Colclough, who has worked with Harry on the Games through Help for Heroes, a U.K. military charity. "We are seeing a level of skill, commitment and maturity in a 30-year-old Prince Harry that we may not have expected to see a few years ago."
At another of his key charities, WellChild, organizers have seen first-hand the prince's ability to talk to families who have seriously ill children or have suffered recent loss.
"We have Prince Harry on his hands and knees playing with younger children there, and some of the children will want to give him a hug," WellChild CEO Colin Dyer tells PEOPLE.
Those who know him point to his two tours of Afghanistan (in 2008-09 and 2012-13) for helping him mature. On Aug. 10, he wrote movingly in The Sunday Times of witnessing servicemen being medically evacuated due to horrific injuries wrought by improvised explosive devices.
As his work life has grown more focused, he has also continued to deepen his closeness with Will and Kate and is a doting uncle to 14-month-old nephew Prince George.
As for his much-scrutinized love life, after dating Chelsy Davy (who is now working as a lawyer in London) on and off for five years and parting ways with Cressida Bonas in April, he is single again.
Unlike William, whose position as immediate heir to his father, Prince Charles, has a clear path, Harry is at something of a "crossroads," a friend concedes. But as he decides how to make a difference in the long term, he can be proud of pulling off two major feats that are intensely personal to him: the success of Sentebale, a charity he set up a decade ago that benefits young victims of poverty and HIV/AIDS in Lesotho, and the Invictus Games in London.
Together, "they prove what [Prince Charles] always says about him," Colleen Harris, his former rep, tells PEOPLE. "That he is more thoughtful than people give him credit for. He is using his own beliefs and values to create something that has longevity, a legacy."