Richard Briers dies
Briers, who starred in shows such as Ever Decreasing Circles and Monarch Of The Glen, recently blamed years of smoking for his emphysema.
His agent said he died "peacefully" at his London home on Sunday.
Briers will be best remembered for his performance as Tom Good, alongside Felicity Kendal, in the 1970s BBC1 sitcom The Good Life .
The show revolved around a couple who drop out of the rat race in Surbiton, southwest London, to enjoy a life of simple self-sufficiency.
In an interview carried out only weeks ago, the actor told how his health was failing after being diagnosed with emphysema five years ago, which he attributed to years of smoking, although he gave up 10 years ago.
"I was diagnosed five years ago and didn't think it would go quite as badly as it has," he said.
"I used to love smoking. It's totally my fault. 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."
Actress Penelope Keith, who played Margot Leadbetter in The Good Life, said of her co-star: "You will hear a lot of people saying a lot of marvellous things about Richard, and let me assure you, they are all true.
"He was a gentleman, he was a wonderful actor, very, very generous and one of the charming things about Richard was he was so self-depricating," she told Sky News.
Monarch Of The Glen creator Michael Chaplin added: "He was absolute star in every possible sense of the word - not just as a professional ... most precise and brilliant in everything he did.
"He was also just the loveliest man - funny, witty and endlessly kind. It was a real pleasure to have known him and worked with him."
His agent, Christopher Farrar, of Hamilton Hodell, 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."
His varied career saw him narrating the 1970s children's cartoon series Roobarb And Custard, as well as adding his voice to the animated version of Watership Down.
Although long known for his comedy roles in film and TV, a new strand to his career unfolded when he joined Sir Kenneth Branagh's Renaissance Theatre Company in 1987, and went on to work in a number of classical roles.
Sir Kenneth spoke fondly as he paid tribute to Briers, saying: "He was a national treasure, a great actor and a wonderful man. He was greatly loved and he will be deeply missed."
They worked together on Henry V, Peter's Friends, Much Ado About Nothing and Mary Shelley's Frankenstein during their lengthy association.
Rada-trained Briers made his West End debut in the late 1950s in Gilt And Gingerbread, and went on to work on a number of British films - Bottoms Up, Murder She Said, The Girl On The Boat and Fathom, alongside Raquel Welch.
Sunday Telegraph theatre critic Tim Walker told Sky News that Briers had an "appetite for hard work".
"He was a proper, grown-up stage actor," he said.
"Very much respected in the profession. I remember seeing him in London Assurance back in 2010, so quite recently, when he was on great form.
"He'd always say to me: 'Oh, I'm so lucky I'm working and it's amazing they haven't seen through me'. That was very much typical of him and I think, to some extent, his generation."