Prince Harry, who turned 21 yesterday, said he wanted to fight for his country as a frontline soldier but would never hide his passion for partying. Harry, whose mother Princess Diana died in a car crash when he was 12, insisted his father Prince Charles’s new wife Camilla was not “a wicked stepmother” and said his older brother William was his closest confidant. The third in line to the throne, training for an army career at Sandhurst military academy, said he would probably mark his 21st birthday on manoeuvres “in a ditch in the middle of Wales”. Harry, youngest son of heir to the throne Prince Charles, said he then wanted to put his training into practice.

“There is no way I am going to put myself through Sandhurst and then sit on my arse back home while my boys are out fighting for their country,” said the flame-haired prince in a string of interviews to mark his birthday. The prince, dubbed a royal “wild child” and playboy prince for his under-age drinking and drug antics, said he would always have a compassionate side – as he did when working in the southern African kingdom of Lesotho with young AIDS victims. He said he could be a caring prince and a party prince. “I am both of them. Does everyone expect me to be just the caring person and not to have a cigarette, not to have a beer? “I am who I am. I am not going to change,” he said.

In January, Harry sparked international outrage after he wore a Nazi uniform to a costume party two weeks before his grandmother, the Queen, led Holocaust memorial ceremonies. A picture of him in Nazi regalia was taken at a private house party and published in newspapers around the world. “It was a very stupid thing to do and I’ve learnt my lesson. Maybe it was a sign of my own immaturity. That was then, this is now. I am becoming 21 – something like that I will never do again,” said Harry. After a 35-year affair, Prince Charles in April married Camilla Parker Bowles, who Diana always blamed for the break-up of her marriage.

Harry was quick to squash any rumours of bad blood with Camilla, nicknamed The Rottweiler by Diana. “To be honest with you, she’s always been very close to me and William. But no, she’s not the wicked stepmother,” he said. “Everyone has to understand that it’s very hard for her. Look at the position she’s coming into. Don’t always feel sorry for me and William, feel sorry for her.” Harry, who won worldwide sympathy as a forlorn boy walking head bowed behind his mother’s coffin, is irked by media attention and says reading stories about Diana still hurts.

“When my mother died, it was in the papers for whatever it was – 16 weeks solid.” His glamorous mother was the world’s most photographed woman whose life was constantly under the glare of the media. Harry, ever wary of paparazzi hounding him, was fiercely protective of his Zimbabwean girlfriend Chelsy Davy, saying firmly: “That is my private life.”