Take a speech he delivered in Colorado Springs. According to his prepared text he was meant to recall planting a tree in the gardens of the British Embassy in Washington.

Instead he went off royal piste and reminded his audience that this was an activity which "most of my family do nowadays".

A future devoted exclusively to tree planting is one Harry intends to avoid.

For now, he'll mix his work as an Apache helicopter pilot with supporting charitable causes and occasional overseas forays.

His latest one, to the US, has gone well. In a land that regularly commits fairytales to celluloid, there have been some women who've made it clear it's time he made them a princess.

Harry blushed, in the way redheads do, and the headlines of "Harry mania" were born.

The son of Diana - her name still has resonance here - has been praised in the local papers for his "roguish charm"; for being "down to earth"; and for not acting, in the words of one commentator, "like a snobby twit".

The trip has been designed to play to Harry's strengths. At its heart, has been a visit to the American military's answer to the Paralympics.

He is determined to bring the "Warrior Games" for disabled servicemen and women to the UK. This is not a princely pipedream - there are serious discussions going on, behind the scenes, to make this a reality.

The images generated have been in stark contrast to the ones printed in some papers the last time he crossed the Atlantic - when a naked Harry was captured for posterity playing strip billiards in Las Vegas with strangers.

In the eyes of some, his rehabilitation is complete. Little wonder then, that critics of the British monarchy - such as Republic which campaigns for an elected head of state - have argued overseas royal tours are less about flying the flag and more about projecting a positive image of the principals back home.

Success overseas is not a new phenomenon for Harry. In Jamaica, last year, he took on Usain Bolt; he hugged a prime minister who wants to move on from having his grandmother as her head of state; and he executed some nifty moves on a dance floor to a Bob Marley track.

Despite the favourable coverage of his time in the US, Prince Harry harbours a deep disdain of the media. At its most intense after his mother died with the paparazzi in pursuit, it hasn't abated with the passage of time.

He would have appreciated the irony of an erroneous report on a US website which suggested he'd held a private party for 40 friends. The guests at the reception were, in fact, members of the British media.

In the years to come, Harry will continue to struggle with this relationship. The ancient institution he represents would wither if ignored.

He will continue to attract glowing write-ups and critical headlines. He is a mix of the soldier prince; the budding charitable entrepreneur; and the royal who desperately wants to be "normal" (though he admitted recently he's not sure what normal is) and have fun - though never again in Vegas.

Harry sticks to the script. Most of the time.

It is not Beatlemania. Nothing like it. But it is an indication of the interest there is here in the unmarried son of Diana.

For an ancient institution that needs to be noticed, the cheering of wannabe princesses does not harm.

But from a palace perspective, this trip will have failed if the talk is only about an eligible bachelor and the suitors who want to settle down with him.

The prince - a more complex character than the caricature of a playboy prince conveys - is in the US to focus attention on landmines, on the work being done with injured service personnel, and on some other charities he supports.

That will be his focus in the coming days. Others, in a land where fairytales are regularly committed to film, may have a different focus.

This time, a fully-clothed prince will once again attract attention in a country which dispensed with the institution he represents centuries ago, but which remains fascinated by it.

His high profile visit comes at a time when the talk is of the Queen reducing her workload and of others stepping up to the mark. Harry, the soldier prince, will - with his brother - help to fashion the future direction of the monarchy.

In Washington, he'll support a cause embraced by his late mother - landmines. When Diana called for an international ban, seven months before she died, a Tory minister accused her of being a "loose cannon".

The princess's son has vowed to finish the work of someone, he said, "had more guts than anybody else".

The 87-year-old monarch won't have arrived at it lightly - she hasn't missed a heads of government meeting since 1973 and she regards the Commonwealth as an important dimension of her reign.

It is an acknowledgement of her advancing age and not, her officials insist, in order to avoid the political question about whether or not Sri Lanka should be the host in the first place.

The focus of campaigners, who are critical of Colombo's human rights record, will now be the Prince of Wales.

Behind the scenes, the ground has been prepared for him to become the organisation's next head - a position he's not automatically entitled to.

His attendance, in November, in place of his mother, will be another very visible sign of his preparation for kingship.

Commonwealth faces 'real test' on Sri Lanka

In the 1970s, Prince Philip declared on American television they were in the red and might need to move into smaller premises.

Later in the 1990s there was public disquiet over an initial plan for the taxpayer to foot all of the bill for repairs following the Windsor Castle fire.

And Prince Andrew will never shake off the tabloid label of "Air Miles Andy" for his past fondness of flying in general - and helicopters in particular.

Now, the institution has bucked the trend for public bodies - and indeed ordinary households - in these austere times and received a pay rise.

Supporters say the new funding will make the royal household more transparent and accountable.

Republic, which campaigns for an elected head of state, argues the increase in money going to the monarch is "absurd and immoral".

The Australian prime minister survived a leadership challenge; reshuffled her cabinet; and apologised to the victims of her country's policy in the past of forced adoptions.

But an answer she gave in parliament doesn't appear to have registered at all.

It was in response to a question about the Commonwealth Charter.

The organisation's attempt to set out, for the first time, its core principles is not a topic which obviously excites the minds of headline writers. But what Ms Gillard had to say was significant and potentially historic.

The key passage was delivered as the prime minister paid tribute to the "distinguished" service of the Queen as head of the Commonwealth over many decades.

She went on to say this: "The institution of the head of the Commonwealth, standing as it does above individual governments, has been an asset of the Commonwealth since its foundation, and we need not be reticent about its future.

"For Australia's part, I am sure the Queen's successor as monarch will one day serve as head of the Commonwealth with the same distinction as her Majesty has done."

This straightforward and clear statement that the Prince of Wales will one day follow in his mother's footsteps - as the symbolic head of a body which represents 30% of the world's population - is striking for a number of reasons.

Until recently, it had been the accepted view that Charles, unlike Elizabeth, would not automatically take on this role.

The heads of government of the 54 countries would have to decide what to do when the prince became king.

But that accepted view has been challenged gently in recent weeks.

As I have written before, the Commonwealth secretary-general, Kamalesh Sharma, has spoken of how Prince Charles' support for the Commonwealth had "deepened" its links to the Crown.

And, at the same event, the Queen thanked Mr Sharma for his "thoughtful" words about the "enduring value" of this bond.

Added to these remarks, we now have Ms Gillard's far from opaque or delphic comments.

They have added resonance because of her view of the value of maintaining Australia's link with the British crown.

She's made it clear she would favour her country becoming a republic once the Queen is no longer on the throne.

So, she clearly envisages a future where Charles would not be her king but would be head of the Commonwealth.

Her endorsement of that role is an important one for the heir to the throne.

The days and weeks after he fulfils his destiny could be tricky ones.

He has his critics, countries other than Australia could seek to remove him as their head of state, and uncertainty over whether or not he would take on the Commonwealth could prove to be destabilising.

Julia Gillard has sought to remove that uncertainty.

One has to assume that her public statement followed private soundings. The mood music, for now, is that a body born out of the collapse of the British empire appears content to have an unelected monarch as its next head.

This will bolster the reign of Britain's next sovereign.

Without fanfare or fuss, a republican named Julia has come to the aid of Charles, a future king.

Her prolonged illness means she has pulled out of two more events in London. It has been bitterly cold outside - but inside Buckingham Palace she will attend a Privy Council meeting on Wednesday and hold an audience with David Cameron.

The mood music from officials remains upbeat. During her brief spell in hospital, doctors are bound to have carried out tests to reassure themselves that her current bout of ill-health has not been caused by a potentially more serious underlying problem.

The 86-year-old monarch "hopes", in the words of Buckingham Palace, to be fully functioning by next week.

If not, more searching questions may be asked about the health of Britain's head of state.

After a week of cancelled appointments, Monday night's Commonwealth reception was the first time the 86-year-old monarch had been seen and heard in public.

On the surface, the event was held to launch the new Commonwealth Charter which outlines the organisation's key principles.

But beneath the surface - in a blink and you'd probably have missed it - were hints about the possible future direction of this body borne out of the demise of the British Empire.

The Queen took on the position of symbolic head from her father. It has afforded her a continued global role.

The former foreign secretary, Douglas Hurd, has spoken of it being a "vivid part of her life". In the words of one who used to work with the Queen: "Her role is unfettered. She likes that."

But who will succeed her? It was once accepted that Prince Charles would not automatically become Head of the Commonwealth.

The website of the Commonwealth Secretariat used to state this fact very clearly. In the last day or two, that reference has been removed, though officials insist it is still up to the leaders of the 54 countries to decide who will, one day, replace the Queen.

Which brings us to the hints at Monday night's reception.

The secretary general, Kamalesh Sharma, spoke of how Prince Charles's support for the Commonwealth (and that of other royals) had "deepened" its links to the Crown.

For her part, the Queen thanked Mr Sharma for his "thoughtful" words about the "enduring value" of this bond.

Those around the Commonwealth secretary general argue his speech was all about honouring the Queen.

But her aides believe this was the first sign that this voluntary association of countries - the vast majority of which were once under British rule - is moving towards there being a natural succession from sovereign to heir.

To understand the importance for Charles of this being resolved, one has to reflect on the alternative.

When he becomes King he could well face criticism of his style of operating - Jamaica, Australia and other realms may use the moment to move on and seek a home-grown head of state - and he could be subjected to days of questions being asked about his suitability for the post of head of the Commonwealth.

If the question is resolved in advance, in his favour, it would bolster the reign of Charles as King. The alternative could undermine it.

In the past, the Queen's eldest son was thought to have displayed a lack of enthusiasm for an institution which his mother has championed even when her government-of-the-day has been less keen.

Now, his office insists it is something he actively supports, having visited 33 member countries.

Critics of any move to secure the Commonwealth role for Charles are likely to maintain, as they have in the past, that an unelected head of state is not an obvious 21st century figurehead for an association that espouses the virtues of democracy.

The hints and the discussions behind closed doors are all about the legacy of a mother and the future of her eldest son.

She has an attachment to the Commonwealth which has not always been shared by her government of the day.

The association of countries - almost all of which were once under British rule - has afforded the Queen a continued global role long after the empire that her ancestors once ruled had gone.

But given that her illness is still lingering, her doctor will have advised the 86-year-old monarch to avoid sitting through a lengthy service in an ancient, draughty abbey.

She may well miss more public engagements later this week.

But officials insist the Queen is not bedridden and her failure to shake off the virus is not something to "fret about".

Then she was having a non-cancerous growth removed from her face and an operation on her knee.

Now, as a precaution, says the palace, she is being assessed for what it's calling "symptoms of gastroenteritis".

British monarchs, unlike present day American presidents, aren't obliged to publish detailed medical bulletins.

So, we know the 86-year-old monarch is said to be in "good spirits" and isn't bedridden, but the nature of her treatment hasn't been made public.

It could include tests to establish if the symptoms she's been suffering from have been caused by an infection or an underlying problem.

As things stand, the Queen is expected to leave hospital soon and at some stage she will resume the role to which she has committed much of her adult life.

For a woman who has lived for decades on a very public stage, this is information she regards as private.

So, for this first hospital stay in 10 years, we know the 86-year-old monarch is in "good spirits". She is not bed-ridden. She has been up and about.

Officials say she will be assessed over the next two days.

Her treatment for a condition which can cause vomiting and diarrhoea, and which her aides will not discuss, could include re-hydration and tests to establish if the illness has been caused by an infection or an underlying problem.

Her brief time in hospital will offer the Queen time to rest and give her staff an opportunity to examine the workload of an octogenarian who has no intention of retiring.

So it's unusual for her to pull out of an official engagement. The last time was five months ago when she had a bad back.

While she rests at Windsor Castle this weekend, her doctors and officials will have to decide whether or not she is well enough to fly to Rome next week. She has been invited by Italy's President Giorgio Napolitano.

It will be an encounter between an elected head of state who is retiring and a hereditary monarch who continues to reign.

As well as a formal ceremonial welcome and a private lunch, the Queen is also due to visit the Pantheon, the ancient Roman monument where two Italian kings are buried.

Theirs was a monarchical dynasty less fortunate than the House of Windsor.

Back in 1981, when Lady Diana Spencer first entered the public consciousness, the Queen told photographers at Sandringham: "I wish you would go away."

They didn't and they won't - images now of a pregnant duchess can command a six-figure sum.

So far, the response of the royals has been restrained in their choice of language and action. No talk yet, in public at least, of seeking legal redress.

If it was pursued, the argument would be that on a private holiday, on a private beach, on a private island, William and Kate are entitled to a reasonable expectation of privacy.

The soon-to-be parents have escaped the climate of austerity and the wintry weather.

They haven't escaped what William sees as one of the downsides of his destiny.

The future king and queen have no doubt been afforded the former; but not, we now know, the latter.

The publication of photographs of a pregnant duchess in a bikini is a reminder of the commercial value of such pictures and of the enduring worldwide interest in the newest member of an ancient institution.

Other European publications may follow the example of Chi. British newspapers, with a decision on Leveson still looming, probably won't.

The royals have complained. The printing presses will still roll.

For William, there will be faint echoes of his mother's experiences.

A bracing holiday at Balmoral or Sandringham may suddenly appear attractive.

It is only in these conditions that the senior royal - for the second time in his life - feels "normal".

"I'm one of the guys .I don't get treated any differently".

With his return to a palace, that will change.

He will have some leave; represent the UK abroad in the coming months; become an uncle; and face renewed questions about when he will "settle down".

His inquisitors will include members of the media - an industry which, like other royals, he dislikes intensely ever since, in his words, he was "very small".

At 28, Harry is determined to be an army officer; a royal; and someone who works hard and plays hard.

As he gets older, he'll face more pressure to jettison the "party prince" image.

When these different worlds collide there is a cost, as Prince Harry knows only too well.

It is only in these conditions that the senior royal - for the second time in his life - feels "normal".

"I'm one of the guys. I don't get treated any differently".

With his return to a palace, that will change.

He will have some leave; represent the UK abroad in the coming months; become an uncle; and face renewed questions about when he will "settle down".

His inquisitors will include members of the media - an industry which, like other royals, he dislikes intensely ever since, in his words, he was "very small".

At 28, Harry is determined to be an army officer; a royal; and someone who works hard and plays hard.

As he gets older, he will face more pressure to jettison the "party prince" image.

When these different worlds collide there is a cost, as Prince Harry knows only too well.

Bills as varied as the 1998 Data Protection Act and the 1996 Housing Act needed the approval of either the Queen or Prince Charles before becoming law.

Those seeking an elected head of state describe this as real power in the hands of the Windsors which is an affront to democracy.

Royal officials point out that no government bill has been objected to in modern times and the requesting and granting of consent is made public.

Even so, the process until now hasn't registered on the public consciousness.

Critics call it a royal veto which needs to be scrapped.

Supporters suggest it merely amounts to royal rubber stamping.

It is yet another reminder of the complex nature of the parliamentary process.

For many others, it was a unique moment which probably hasn't been seen in peacetime for three centuries.

For the Queen, it was a reminder of where the power lies and how much has been lost from the position she occupies.

Her prerogatives or privileges are now pretty much limited to appointing a prime minister and dissolving Parliament. In both cases, she's severely limited by constitutional conventions.

Rather than ruling, like her ancestors, she reigns - to the delight of many and the irritation of those seeking an elected head of state.

The Queen left the cabinet meeting with 60 table mats, safe in the knowledge that, once again in her long reign, she has made history.

In pictures: The Queen attends cabinet

If William and Kate's first born is a girl, she will be queen even if she is followed by a younger brother.

Other royals will also benefit.

The Queen's cousin, Prince Michael of Kent, was once 8th in line to the throne. Marriage to a Roman Catholic helped put pay to that.

Now, with the disqualification if one marries a Catholic to be removed, Prince Michael will rejoin the line of succession.

So too, will one of the Duke of Kent's sons. But neither should raise their hopes as they will be very low down the list of potential future monarchs.

The proposed law also does not touch what one Scottish cardinal has called "state sponsored sectarianism" - the ancient ban on a Catholic becoming sovereign.

The prince with a destiny to fulfil one day has to decide what to do in the meantime.

His current stint as an RAF search and rescue pilot, based in Wales, is coming to an end.

The remoteness of Anglesey, which was attractive to them when they were newly-wed, poses problems once they have a family and her relatives are some distance away.

William could move to another search and rescue base; pursue a different career in the military; or surprise, once again, the royal experts with an imaginative solution to the problem of what to do with the second-in-line to the throne.

The fourth option, becoming a full-time royal, is the one the 30-year-old is reluctant to embrace.

He knows what awaits. He doesn't want to rush there.

Severe morning sickness can be 'traumatic'