Actor Richard Briers, best known for his role in TV's The Good Life, has died at the age of 79, his agent has said.
The star, who was also an accomplished stage actor, had been battling a serious lung condition for several years.
Briers died "peacefully" at his London home on Sunday, his agent added.
Briers recently blamed years of smoking for his emphysema.
"It's totally my fault," he said. "So, I get very breathless, which is a pain in the backside. Trying to get upstairs... oh God, it's ridiculous. Of course, when you're bloody nearly 80 it's depressing, because you've had it anyway."
His agent, Christopher Farrar, said: "Richard was a wonderful man, a consummate professional and an absolute joy to work alongside.
"Following his recent discussion of his battle with emphysema, I know he was incredibly touched by the strength of support expressed by friends and the public.
"He has a unique and special place in the hearts of so many. He will be greatly missed. Our thoughts and deepest sympathy go to his family at this sad time."
In 1970s BBC sitcom The Good Life, Briers and Felicity Kendal played a married suburban couple who try a self-sufficient lifestyle.
Briers also starred in shows including Marriage Lines, Ever Decreasing Circles, Monarch Of The Glen plus a role in Doctor Who and Torchwood.
He appeared in many films, most recently in British comedy film Cockneys versus Zombies, plus a cameo role in Run For Your Wife, based on Ray Cooney's 1980s stage farce.
Briers narrated the 1970s children's cartoon series Roobarb And Custard and also provided the voice for the character of Fiver in the animated feature Watership Down (1978).
"The nation has lost one of its most favourite actors of all time," said Michael Grade, who ran BBC One when Ever Decreasing Circles was on the air.
"He was up there with Ronnie Barker and Alan Bennett. He was just a treasure. He was so warm and so gently funny, and such a truthful actor."
Speaking to 5 live, Lord Grade added: "If you treated him like a star, I think he got embarrassed. He was one of those wonderful, genuine, professional actors with real star quality but humility to go along with it.
"There was nothing he couldn't do, and he always had a twinkle. You were always pleased to see him. It's just a shock and really, really sad."
"He is a centre-piece of our humorous culture and a magnificently talented man. I'm so deeply sad today that he has left us. He was a great person."
Actress Penelope Keith, who played the snobbish neighbour Margo to Briers' character Tom in The Good Life, said the actor's death was "an enormous loss".
"I look back with enormous affection and love for Dickie. He was the most talented of actors, always self-deprecating. I learnt an awful lot from him during our time on The Good Life," said Keith.
"He was a wonderful mentor, tutor and teacher although that would suggest he imposed himself on you, which he didn't.
"He was always courteous and he would speak to the crew - which was not always that common. And he was always nervous. It was the most enjoyable time - when I think of The Good Life, I smile."
Briers's godson, the actor and director Samuel West, whose mother Prunella Scales was in Marriage Lines, tweeted: "What a lot of joy he spread."
Scales described Briers as "very skilful, very professional, and off screen a dear friend and a very considerate colleague".
Comedian and writer Barry Cryer told 5 live Briers had been an "enormously popular, well-liked man", adding he was a "formidable actor and the most modest, you know, arrogant in his humility!".
After a long career in popular television, Briers joined Kenneth Branagh's Renaissance Theatre Company in 1987, and his career moved on to major classical roles.
He said at the time: "Ken offered me Malvolio in his production of Twelfth Night at the very time I had decided to expand my career when I realised I had gone as far as I could doing sitcoms. As soon as I worked with him, I thought he was truly exceptional."
After playing Malvolio, Briers took on the acting challenge of King Lear, followed by the title role in Uncle Vanya and Menenius in Coriolanus.
Peter Egan, his co-star in Ever Decreasing Circles, told the BBC: "I spent nearly 10 years just laughing. He was just the most magical comedian, a huge talent, has been a part of the nation's lives for over 50 years.
On film Branagh cast him as Bardolph in Henry V (1989), as Stephen Fry's father in the comedy Peter's Friends (1992), Don Leonato in Much Ado About Nothing (1993), the blind grandfather - playing opposite Robert De Niro's Creature - in Mary Shelley's Frankenstein (1994).
Sir Kenneth said on Monday: "He was a national treasure, a great actor and a wonderful man. He was greatly loved and he will be deeply missed."
Stephen Fry tweeted: "How sad. He was the most adorable and funny man imaginable."
Briers was born in London on 14 January, 1934 and was inspired to be an actor by his mother, a music and drama teacher.
He trained at the Royal Academy of Dramatic Art, and won a scholarship to Liverpool Playhouse in 1956. Two years later he made his first West End appearance in Gilt And Gingerbread.
His big screen career began with the British features Bottoms Up (1960), Murder She Said (1961), The Girl On The Boat and A Matter of Who (both 1962) and the multi-national The VIPs (1963), followed by Raquel Welch's spy spoof Fathom (1967).
Other film credits included Michael Winner's A Chorus Of Disapproval (1989) and the big-screen version of the hit TV series Minder.
Briers returned to the stage many times in his career, and was particularly associated with the works of Alan Ayckbourn, including Relatively Speaking, Absurd Person Singular and Absent Friends.
He was formerly president of Parkinson's UK and later its honorary vice president.
"We're really sad to hear that Richard Briers has passed away. Richard was our honorary vice president and a great supporter of Parkinson's UK," the charity tweeted on Monday.
Briers was awarded the OBE in 1989 and a CBE in 2003. He married the actress Anne Davies in 1956 and had two daughters with her.