They have been part of our lives since they were just ten-years-old and foisted upon the world as the wide-eyed stars of the Harry Potter movies.
Now, they're all grown up with millions in the bank, universal fame and five of the biggest blockbusters ever made under their belt.
Magical: Rupert Grint, Emma Watson and Daniel Radcliffe have five of the biggest blockbusters ever made under their belts
In Harry Potter And The Half-Blood Prince, their sixth and latest film, their alter egos Harry Potter, Hermione Granger and Ronald Weasley fall in love and come of age.
But while Daniel, 19, Emma, 19, and Rupert, 20, having worked almost solidly since they were 11 and grew up early, they are contemplating a different leap into the unknown: life after Harry.
'It's going to sound dramatic, but I feel like my life as I know it will be over,' says Emma.
'My whole life has been about Harry Potter and then all of that will shut down and I don't know what it will be like.'
They are currently filming the last book of JK Rowling's series, Harry Potter And The Deathly Hallows, which is going to be split into two films for release in 2010 and 2011.
And then there will be no more Harry. 'When we started, we were so young,' says Emma recalling the franchise's early days.
'I think we probably had to grow up quicker than other children do. We had a lot more responsibility. In that sense it was difficult; there was a lot of pressure.
Evanna Lynch, who plays Luna Lovegood
'For the first two films I was just getting to grips with being on a film set. I was just like Hermione for those early films - I didn't need to act that much because I was that little girl.
'Now, sometimes I have to bring myself back to Hermione, as she is so innocent and naive that she is really very vulnerable. I consider the Potter films as being like my academy; the way I have learned how to be an actress.'
She is due to attend the prestigious Columbia University in New York later this year where she hopes to be a 'normal teenager who happens to act'.
Her co-stars, meanwhile, admit to some concern about what happens now. 'It feels like it is all coming to an end,' says Rupert, who recently completed filming Wild Target as an apprentice hitman alongside Bill Nighy.
'I'd like to continue acting if I can. It's always at the back of my mind that acting might come to an end for me when Harry Potter finishes. I don't know if I'm good enough to have a long career.'
Daniel, whose easy confidence and quick wit make him seem older than his years, is more hopeful and says he plans to keep on making bold moves in the acting world such as his acclaimed naked West End and Broadway performance in Equus.
'I want to be an actor and I think the greatest quality you can have is a fearlessness and willingness to try something even if you think you might fail,' he says. 'To try it anyway is to have a bravado that I aspire to.
'I am going to be so sad to leave this behind. To work with such an incredible crew of people was a real privilege and probably one I will never enjoy again.
'But there is also an element of excitement that a script might come in and I don't have to go: "Oh, I'm sorry I'm kind of busy being Harry Potter for the next four years.'' '
With Harry Potter And The Half-Blood Prince, the stories about the little English wizard are due to take over from James Bond as the most successful movie series ever made.
At the box office alone, the films have made £1.9billion and DVD sales have accounted for £1.7billion.
Tension: Ron (left) and Hermione finally realise their feelings for each other
Another £600million has been made from video games while, merchandise accounts for sales of hundreds of millions more. Each of the young stars is now very famous and very rich: Daniel is said to be worth £30million, Emma £10million and Rupert £5million.
Yet they are each well-behaved, polite, articulate and down to earth, in contrast to the legions of child stars who have found the spotlight too much to cope with.
To the disappointment of a waiting public, not to mention the paparazzi, none of them has done anything remotely like go off the rails.
The most outrageous thing any of them have spent their money on is Rupert's herd of pigs and an ice cream van. The biggest thing Emma has bought herself is a second-hand car.
And they laugh off their star status. Asked about being a heartthrob, Daniel jokes: 'Yes I go to Japan and they all scream and they go mad all over the world. But that is a different type of me.
'That's the me who is on the red carpets who lots of people are attracted to. But the me who sits in a darkened room for eight hours watching cricket and eating pasta in my socks and my underwear is not nearly as appealing to women.'
Interrupted: Harry Potter and Ginny Weasley's first kiss is brought to an abrupt halt by an unexpected visitor
They all attribute their good behaviour to the example set by their film colleagues.
'Everyone is so enthusiastic that it has really rubbed off on the rest of us,' says Bonnie Wright, 18, who as Ginny Weasley has appeared in all the movies and gets to kiss Harry in the latest one.
'The ethos is that everyone is totally dedicated to these films.
'Of course, there are the premieres and red carpets that surround us, but for me it's about being on set. And I know that is the same for all the kids and that is what keeps us grounded.
'Other people in the films, such as Alan Rickman, Michael Gambon and Maggie Smith, have continued being such amazing actors by being very true to their job. You get a lot of inspiration from them.'
She adds her belief that it is no coincidence they have all turned out so well: 'I think the producers were looking for the right children at the auditions all those years ago - not just whether we could act and look the part.
'A lot of the casting process was about discovering the child. At my auditions, I read through the script and then they asked me about myself and why I'd like to have this experience. I said I would love to meet new people and learn something I didn't know about.
'I think if someone had come in and said "I want to be famous", they would have said: "Next!" That's not what they wanted. This isn't something I really thought about before, but if you look at how everyone has turned out there must have been an element of choosing kids who were confident and calm.'
All insist, as well, that unlike their film counterparts, none of them has ever hankered over each other romantically. 'I'm sorry, we're really boring,' says Emma. 'We know it would be of huge interest if we hooked up.
'But we have grown up together and there is nothing between the three of us or any other members of the cast.'
Bonnie adds: 'The filming experience is so intense that we are more like brothers and sisters than friends, and that's why none of us could contemplate it.'
Harry Potter And The Half-Blood Prince, the sixth film in the box-office juggernaut, is the most adult yet.
While it isn't exactly Trainspotting, it's got sex, it's got bad behaviour, the poignant death of one of its protagonists and it's even got drugs.
'Everyone is a little bit older now and the hormones are really starting to fly,' says director David Yates. '
This film marks a real transition point between our cast as children and our cast as adults. It's more mature, more complex, more intense.'
So in this latest film we have several complicated love triangles.
Ron (Rupert Grint) secretly loves best friend Hermione ( Emma Watson ) and she secretly loves him but is devastated when he hooks up with the over-affectionate Lavender Brown.
Harry falls for Ron's little sister Ginny (Bonnie Wright), but is terrified about what his friend will think. Meanwhile, Ginny has always had a crush on Harry but she is already dating someone else.
Harry had his first kiss in the previous movie, The Order Of The Phoenix, but when he finally does hook up with Ginny it is a spellbinding moment, as much of the film leads up to it. 'It took us two days to film the kiss,' says Bonnie, 18.
'And the difficult thing was actually more about the emotion than the physicality of the kiss.
'I was nine and Dan was 11 when we first started working together and suddenly we had to look at each other in a different way.
'I was nervous the first time we kissed, but after the first one you get into it - you close your eyes and it just happens.'
Meanwhile, the students' experiments with love potions and luck potions bring some of the funniest moments seen in a Harry Potter movie.
'Yes, there are a few drug metaphors in the film,' admits Daniel. 'I think any film now that is marketed in the main for children still has humour that works on one level for them and on another level for adults.'
There are also some vivid scenes which take the stories forward a step: one sees London's millennium bridge being torn apart by the Death Eaters.
In another, Harry and his nemesis Draco Malfoy have a vicious fight, while a murder at the end makes events even more frightening and confusing.
The producers admit that in making the film so grown-up they did worry that they could put off their core audience - the young fans who love the books.
And at initial screenings some of the youngest fans were said to have disliked all the kissing.
However, they insist they are confident in their film, which has been lauded with praise by critics. 'We are only making what the writer J.K. Rowling is giving us,' says David Yates.
'We had a screening a week ago with a very young audience and our concern was that the film would be a bit beyond them, but they came out of it with their eyes shining.
'They really responded to the maturity and the intensity of what we are doing.
'They like not being patronised. They like being given something which is just beyond their fingertips' reach. They like being frightened.'
Daniel adds: 'If they don't like the kissing scenes, they could always cover their eyes for a minute.'
And producer David Heyman insists: 'The parents are more worried than the children themselves about the films being dark.
'This film is more mature because of the depth of the character work. Children like to be challenged.'
Work will finish on the final chapter of the Harry Potter epic next spring and David Yates, who is also directing the last two films, insists they will be even better than anything that has come before.
'Everyone has it at the back of their minds that this great juggernaut is reaching the end of its journey,' he says.
'Everybody wants to do their best work, as they know they won't get another chance.'
Emma insists that while the Harry Potter story might soon be over, it will never really disappear.
'I am a huge fan of the books,' she says. 'I think every generation will bring a new round of children to them and hopefully to the films. I would love them to become classics.'
• Harry Potter And The Half-Blood Prince is out in cinemas on July 15.