With his trademark baseball cap, the geography major (in 2003) tries to blend in at school. Photo by: LANDOV
A Tale of Two Princes| Prince Harry, Prince William
Yet he also visited AIDS hospices during a two-month trip to Lesotho earlier this year. "I have a lot of my mother in me," he said. "This is my side no one gets to see." Diana's influence doesn't end there. There were even shades of the princess in Harry's dustup with the paparazzi, says author Lacey: "If Harry's cradling AIDS-suffering children is learned behavior from his mother, then so is this."

William, as a future king, has followed in the more measured footsteps of his father. The fourth-year geography major has kept his head down, even giving up his captaincy of the water polo team to concentrate on exams, aides said. He has stuck, so far, with just one girl – housemate Kate Middleton, 22, and the pair keep a low profile. And apart from the occasional fuzzy vacation snap, he has, for the most part, avoided the paparazzi trap. In August he even made it through a visit to a longtime friend in Franklin, Tenn., virtually undetected. What's a typical photo of William? Those taken at royal photo ops, like the one last May with dad at Highgrove, the family's Gloucestershire farm, where he gamely checked a sheep for foot rot. "I am a country boy at heart," he declared last year.

Of course, the heir to the throne and the second-born "spare" face different pressures. Harry "almost lives in the shadow of his older brother," says Ken Wharfe, former bodyguard to Diana and her sons. While William has always known what he had to be, Harry was somewhat rudderless. Just 12 in 1997, "he was at a particularly vulnerable age when Diana died," says a family friend. Adds a source who has known the princes for years: "When Harry went through all those teenage growing pains, hormones raging and the pressure of exams – that's when they need their folks around. During that period boundaries are set. I just don't think that happened for Harry." What about Dad? "I don't think Charles knows how to get involved," says a royal insider. "So much of his life is done by other people. He tries. He knows Harry is missing something."