Lord Richard Attenborough has led tributes to his close friend, Sir John Mills, who has died aged 97.
Sir John Mills was Lord Attenborough's 'oldest friend'
"He was a very remarkable man. He was adored by the people he worked with and he will be hugely missed," he said.
"There was nobody comparable really who gave such a variety of absolutely impeccable performances.
"He never stopped work - work was everything. He was immensely proud of his profession and he brought great honour to it," he added.
A Buckingham Palace spokeswoman said the Queen had been "sorry" to hear of the actor's death.
Tony Blair described him as "a great actor, a true gentleman and a loyal friend; someone who made us proud to be British".
Actor Corin Redgrave said that he "disguised his contribution, which was enormous I think, behind a veneer of modesty".
He said of him: "He had something about him - a look in the eye, the manner of walking, the manner of delivering his speech - which - if you think of great film performers like Henry Fonda, their image stays in your mind even longer than the parts they played ".
Speaking on BBC Radio 4, Lord Attenborough recalled the moment they first met.
"It was 65 years ago. He was the star of a movie called In Which We Serve - in which I had my very first job."
The 81-year-old added that the pair became close friends, with Sir John almost acting as a father figure to him and his wife.
Sir John won his only Oscar in 1971 for Ryan's Daughter
"He is my oldest friend and he's been a sort of hero to me in a way.
"He and his wife Mary almost adopted my wife and me a number of years ago. He really kept a fatherly eye on almost everything I did.
"I not only acted with him in a number of movies, but also he played in most of the movies that I directed - Winston, Oh What A Lovely War, Gandhi and so on.
"He went into hospital about four or five weeks ago with a chest infection that was never overcome. I saw him every other day virtually, I think, during that period and I shall miss him very much."
When asked what he thought Sir John's greatest role had been, Lord Attenborough said it was the part of Willie Mossop in the 1954 film Hobson's Choice, directed by David Lean.
"It was probably as perfectly adjudged a film performance as I have ever seen - given by anybody. He was quite miraculous in it.
"He was a wonderful comedian too - he told stories, he was always making you laugh.
"In terms of his comedy character acting, he could play this absolute elemental figure of Willie Mossop, this local laddie from Lancashire.
"He managed to give the man great dignity while at the same time finding the ability to inject a huge humour in the characterisation. It was quite marvellous."