Geoffrey Rush has been Oscar-nominated for his portrayal of Lionel Logue
King George VI's speech therapist Lionel Logue never swore in front of the monarch in real life, his grandson has said.
Robert Logue and his sister Alex Marshall attended the premier of Oscar-nominated film The King's Speech, which depicts their grandfather's struggle to help the king overcome a stammer.
The brother and sister, from Rutland, said the movie had brought home to them what a "special man" their grandfather was.
The film also highlights how the unconventional speech therapist became close personal friends with the royal.
Multi-award winning actor Geoffrey Rush plays the part of Lionel in the film.
Alex said she had found watching the movie "quite frightening" to begin with, but as it progressed she became mesmerised by Rush's interpretation of her grandfather.
"It just brought it home what a very special man he was really. I really enjoyed it, I thought it was great," she said.
"I know my grandfather had certain hand movements and I wonder who he'd got that off, because nobody else would know. But there were certain things that I recognised."
Robert said he had found the dramatisation very interesting, if not entirely factual.
"Although a lot of it is not strictly accurate, for instance I don't think he ever swore in front of the king and he certainly never called him Bertie, you've got to make a film and it all comes together," he said.
He was also impressed with the performances in the film.
"Colin Firth you think is going over the top, but then you listen to the original broadcasts [of King George VI] and that opening shot in the film is dead right."
However, he feels the most compelling aspect of the film is how it highlights the wonderful and lasting friendship between his grandfather and the king; a friendship that he hints was not entirely celebrated by all.
Colin Firth had to learn to stutter for his performance as King George VI
"It was a very personal relationship, no question about it and it had a certain amount of antipathy from the royal family I think. We could tell you all sorts of stories," Robert said.
"We do know the Queen Mother wasn't particularly keen on the Logue relationship because she wanted to be the one seen to cure the king."
The brother and sister share fond memories of their "very Victorian" relation, who they describe as "kindly" but not over familiar, in "lovey-dovey" way.
Each December Alex and Robert travelled with their parents to London to spend Christmas with Lionel and his wife Myrtle.
The family would wait until the afternoon to eat their festive dinner as Lionel would be in attendance at the palace, sitting by the king as he read his annual Christmas speech.
Alex remembered: "I think we knew he was quite an important person, though we didn't really talk about it a lot."