Prince Charles celebrated his 40th birthday Monday with a trip to Birmingham for an inner-city "street party," and the Defense Ministry promoted him to Royal Air Force colonel and Navy captain.

As he crosses into middle age, the heir to the British throne, who has no constitutionally defined job, has carved his own role - as crusader for the underprivileged and protector of the environment.On the eve of the prince's birthday, one of his close associates, Tom Shebbeare, said Charles is irritated by the news media's obsession with peddling what he called "tittle-tattle" and fiction about Charles' private life, which he said distracts from the prince's serious work.