No one likes being sick. But Queen Elizabeth's outspoken, and at times curmudgeonly, husband of 65 years will undoubtedly have no patience whatsoever with the latest illness that curtailed his activities and put him in hospital for the third time in nine months.

The 91-year-old Duke of Edinburgh was discharged from the Aberdeen Royal Infirmary in Scotland on Aug. 20, after spending five days there for treatment of a recurring bladder infection. In the short term, the doctors' directives to the 91-year-old Prince Philip as he recovers will be clear: take it easy, relax, rest. But that's never been his nature.

Queen Elizabeth and Prince Philip watch the proceedings from the royal barge during the Diamond Jubilee pageant on the River Thames in London on June 3, 2012. (John Stillwell/Associated Press)

In the longer term, though, this latest illness of the longest-serving royal consort in British history could have a subtle yet significant impact on the evolution already underway at the House of Windsor.

"Certainly it will be a change within the Royal Family if Prince Philip … increasingly withdraws from public life because of his health, as the Queen has always been seen by the public as part of a married couple," says Toronto-based royal historian Carolyn Harris.

Not that Philip, who's been out and about at the London Olympics, a regatta and other royal activities recently, will likely want to withdraw.

"If you think of his life before he got married, he was in the navy," says Ninian Mellamphy, a longtime royal watcher and professor emeritus at Western University in London, Ont.

"That was like a club for upper-class men of his sort and he maintained, I think, the attitude of that. He's essentially a gregarious type of person and the whole idea of his fading into the background would be surprising and very unwelcome."

Generational shift

Philip's recent illnesses — including the bladder infection that hit him during the Queen's Diamond Jubilee celebrations in June, heart trouble over Christmas — come at the same time as the House of Windsor is undergoing a carefully managed generational shift that has put the Young Royals, particularly his grandsons William and Harry, along with William's wife, Kate, firmly in the spotlight.

"I think what we're going to see in the future is increased duties by the younger generation of the Royal Family," says Harris, who writes a blog, Royal Historian.

In a media interview earlier this year, William, the second-in-line to the throne, broached that subject head-on.

"Prince William mentioned that he was still deciding between taking another tour of duty as a search and rescue pilot or changing to full-time royal duties," says Harris. "Certainly Prince Philip's health will likely be a factor in that decision."

Prince William, centre, and wife Kate, Duke and Duchess of Cambridge, left, join Prince Harry while watching track cycling at the velodrome during the 2012 Olympics on Aug. 2, 2012, in London. (Matt Rourke/Associated Press)

Media reports in Britain this week suggest that William's Royal Air Force superiors may be looking for a way that would allow him to continue some military work — perhaps as a part-time helicopter instructor — while clearing the way for more time as a working royal.

That search-and-rescue work put William firmly out of the spotlight as the London Olympics drew to an end earlier this month.

He was back on duty in Wales and conspicuously absent at the closing ceremonies. Younger brother, Harry, however, couldn't have been more conspicuous, standing in for the Queen.

"In 2012, there's been a real increase in Prince Harry's responsibilities," Harris notes.

Leaving the nasty headlines behind

The 27-year-old once known for his party-hearty ways and ability to grab headlines, not always in a good way (dressing in a Nazi costume at a fancy dress party was not a great idea) seems to have left that life behind him.

Jacques Rogge, left, president of the International Olympic Committee, and Prince Harry attend the closing ceremony at the Olympics on Aug. 12, 2012, in London. (Matt Dunham/Associated Press)

Harris says Harry's closing-night appearance at the Olympic Games suggests that his role as a royal ambassador is not an isolated event.

"He visited Brazil earlier in the year to discuss the transition from the 2012 Olympics in London to the 2016 Olympics in Rio de Janiero, so I think … we’re going to see youth athletics and then the Olympic committee as a part of Harry's public duties going forward."

Throughout the Olympics, William, Harry and Kate seemed to be everywhere, cheering the U.K. team and hanging out with Olympic volunteers, perhaps part of a strategy to make youth athletics a patronage interest for the younger royals.

Harry also visited Canadian athletes at Canada House. Rumours lately suggest Kate, a tennis fan and player, may become vice-patron of the All England Lawn Tennis and Croquet Club, the home of Wimbledon.

Harry's apparent transformation also caught Mellamphy's eye during the Olympics, when the princes were interviewed on TV.

"They came across very, very positively as enthusiasts for the Games and enthusiasts for British participation in it, and they were really very forthright and charming," says Mellamphy.

"I've never seen [Harry] interviewed seriously before and I always saw him as kind of a representative of youth and of perhaps unwise youth, but he came across very well."

Mellamphy chalks up the way William and Harry came across in public at least partly to their mother, Diana, the late Princess of Wales, who died after a car crash in Paris in 1997.

'Very much their mother's sons'

"I think that maybe those two boys are very much their mother's sons, that they have a good deal of that charm that she had.

"At the same time, I suppose the lessons of her life made them a bit wiser than they might otherwise be."

But Mellamphy also sees something of their grandmother, the Queen, in them as the inevitable shift to the younger royal generation takes place.

"These people are obviously being trained in a kind of democratic society rather than in an aristocratic one.

"They seem to speak as if they were … ordinary blokes despite their privileges, so they have that kind of charm that was associated with their mother in her better moments, and a kind of wisdom that seems to belong very much to themselves and might even imitate their grandmother, who seems to be a very sensible woman."

Prince Edward visits Mountain Brook, Ala., on April 28, 2012, for an afternoon tea and presentation of the Duke of Edinburgh Awards. (Jeff Roberts/The Birmingham News/Associated Press)

Of course, there is another generation in the middle, between the Queen and Philip and William and Harry. Harris says that generation — William's father and heir to the throne, Charles, along with his sister, Anne, and brothers Andrew and Edward — were more in focus during the jubilee celebrations, though they also showed up at the Olympics as well.

Edward has also taken on some of Philip's charitable patronages, and rumours and palace mumblings suggest he's in line for his father's title, the Duke of Edinburgh.

For now, though, the family will be hoping Philip recovers from the latest infection, no one more than the Queen.

'Constant strength and guide'

Philip's absence was noticeable during the final days of the celebration of her jubilee. Earlier, she had singled out just how much his constant presence has meant to her.

"During these years as your Queen, the support of my family has, across the generations, been beyond measure," she said during an address to the houses of Parliament in March.

"Prince Philip is, I believe, well-known for declining compliments of any kind. But throughout he has been a constant strength and guide."

She will undoubtedly be hoping he gains that strength again.