HE'S rich, handsome, charming and - unless disaster befalls - destined for exaltation beyond measure. Others may be pretenders to the throne, but there's little doubt that Prince William is truly the most eligible bachelor in the world.

A pin-up for much of his life, the 6ft 3in blue-eyed prince has inherited his mother's looks, as well as his father's brain. Another bequest may not be quite so welcome - the weight of expectation on his shoulders as the monarchy's great hope.

While Buckingham Palace has been keen to promote the prince, William himself has been noticeably reluctant to play the role. Today, he will carry out two public engagements in Wales with his father, as part of the build-up to his 21st birthday on Saturday. But what distinguishes these outings is their very rarity.

When he was 21, Prince Charles had been invested as Prince of Wales; undertaken a solo official visit, to Malta; had given his first public speech, had undertaken a week-long tour of Wales; had attended the State Opening of Parliament and was about to commence an official tour of Australia, Hong Kong, New Zealand and Japan.

For the purposes of State documents, he was known as HRH Prince Charles Philip Arthur George, Prince of Wales and Earl of Chester, Duke of Cornwall, Duke of Rothesay, Earl of Carrick, Lord of the Isles and Barron Renfrew, Prince and Great Steward of Scotland and Knight Companion of the Most Noble Order of the Garter.

William likes to be known as William Wales. He is entitled to use the royal style HRH, but has made it clear he has no intention of using it at least while he is a student at St Andrews University. He has also largely eschewed public engagements, even steering clear of events associated with the Diana, Princess of Wales Memorial Fund.

Although there is occasional talk of the succession bypassing his father, William is said to refuse to even entertain the idea of becoming the next monarch, and instead is content to remain a distant prospect, as the heir to the heir to the throne.

While Harry is prepared to carry out solo public engagements, William's reluctance is said to be partly based on a desire not to be seen to be competing with his father for attention, hence his insistence on accompanying Prince Charles in Wales today.

At university, he likes to be seen as any other student. He shares a house with three other students, and has been photographed shopping in Tesco's. He certainly seems to have settled into university life after a difficult first term, which apparently left him on the verge of quitting.

The Prince is said to be humourous, considerate and a good mimic - with his father and Ali G his best impressions - but a strong character who can be quite stubborn, and has overcome his natural shyness to become a confident young man.

He is a keen sportsman, who enjoys hunting, riding his motorbike and going shooting with his grandfather, the Duke of Edinburgh. He enjoys reading and likes a drink, but has never smoked and is said to steer clear from drugs, unlike his younger brother.

Naturally, the subject of the Prince's love life has been the source of much speculation, with William linked to a string of girls. He has managed to keep many of them out of the newspapers, although at the weekend he took the unusual step of denying claims of a relationship with 21-year-old Jessica Craig, with whom he was said to have made a 'pretend engagement'.

William's reluctance to put himself in the spotlight, perhaps partly informed by the experience of his mother at the lenses of the paparazzi, has helped ensure he has retained a wholesome and relaxed image, although he blotted his copybook at the weekend somewhat with a spot of road rage.

The Prince was said to have behaved like a young yob when he overtook the Earl of Bathurst on the Earl's own estate following a polo match, ignoring both the estate's 20mph speed limit and common courtesy. To compound his offence, he left the apology up to his father. It may have been a one-off, or he may have been trying to ape his younger brother's bad behaviour, but it did mark the first stain on an otherwise unblemished public persona.

With two years left of his university degree, attention will soon turn to the future for the young prince. After the experience of his uncle, Prince Edward, a profession is unlikely. The most probable course is the Army, which would afford a certain degree of privacy, as well as carrying on a royal tradition. A third option, become a full time member of the Royal Family with a packed diary of engagements, seems unlikely given his reticence to participate in public life. In the short term, he is said to be thinking of ditching his history of art course for the easier option of geography.

IN four years' time, when he is 25, he will take control of a legacy from his mother's estate - £21m to be divided between William and his younger brother. Until then, he is given a monthly allowance, although he is often said to complain he is short of cash and has earned a reputation as being tight with money.

But as he makes his way into the world, the chances are he will discover that maintaining his privacy is going to be nigh on impossible. Torn by the twin demands of Buckingham Palace, pushing him forward as the modern and appealing face of the monarchy, and a media and public anxious to know more about the man who would be the 42nd monarch since William the Conqueror, William Arthur Philip Louis Wales may find himself an increasingly public figure, like it or not.

It's a weight of expectation which has driven his father to distraction, bemoaning his fate as a man struggling to find a role. Whether William's broad shoulders can bear such a burden remains to be seen. As he celebrates his 21st, surrounded by family and friends at Windsor Castle on Saturday night, it is a thought which cannot but be the spectre at the feast.