Welsh actor Philip Madoc has died after a short illness, his agent says.
The 77-year-old had a long career on stage and screen, playing the title role in the BBC drama The Life and Times of David Lloyd George.
His agent Michael Hallett said he died on Monday morning in hospital in Hertfordshire surrounded by his family.
Born in Merthyr Tydfil, he appeared in many classic television shows including Dad's Army, Doctor Who, Porridge and the detective series A Mind to Kill.
His extensive radio work included the title role in the BBC Radio 3 adaptation of King Lear and more recently he starred in S4C's new series The Cockle Farmer.
He was also widely remembered for his part as a German U-Boat commander in the classic "Don't tell him, Pike" scene from the popular television sitcom Dad's Army.
Mr Hallett said: "He will be greatly missed by all."
He added that Madoc had had a short illness since January.
His children, son Rhys and daughter Lowri, and his grandchildren were with him along with other members of his family when he died.
In a statement the actor's family said: "He will be greatly missed by his son, daughter and grandchildren.
"Although he suffered from cancer, he was very well looked after by the staff at Michael Sobell Hospice in Northwood, for which the family are very grateful.
"He died peacefully in his sleep, at 9am this morning."
His former wife, actress Ruth Madoc, said she had known for some time that he was not well.
"I've known him since I was 17 and I married him at 19," she said. "We had two children and have five grandchildren.
"I saw him on a regular basis and we had the family in common and a love of the business.
"I've got some wonderful, wonderful memories of Philip. He was such a talented actor and had that wonderful voice."
Rhodri Talfan Davies, director of BBC Cymru Wales, paid tribute to Madoc as "one of the foremost actors of his generation".
Mr Davies described Madoc as "a man of phenomenal talent who will be remembered by millions for his performance in the title role of The Life and Times of David Lloyd George".
"He leaves a rich legacy of work - in both drama and comedy - and will be much missed," he said.
Merthyr Tydfil and Rhymney AM Huw Lewis tweeted: "Sad news about Merthyr's Philip Madoc who passed away today. A truly gifted actor who entertained the nation. He will be sorely missed."
Plaid Cymru Leader, Ieuan Wyn Jones, described Madoc as "a committed friend of Wales".
"Whenever I met him, he was always extremely enthusiastic about Wales' potential as a nation," he said.
Elaine Morgan, who wrote the screenplay for The Life and Times of David Lloyd George, paid tribute to him as "immensely versatile" with "a wonderful voice".
"When he found out there was going to be a series about David Lloyd-George he was hell-bent on getting the part," said Ms Morgan.
"He was successful, of course, and did a great job of it.
"He was just so professional. I think other people liked acting with him because he never tried to shine at the expense of those around him."
"He was always bemused at being remembered for the "don't tell him, Pike" scene from Dad's Army.
"He used to say there were hundreds of episodes of Dad's Army and he couldn't work out why people focused on that one."
Marilyn LeConte, who also worked with Madoc on The Life and Times of David Lloyd George, said he was "a fine actor, and a true gentleman".
"Although he will be probably be remembered for playing roles that required a certain gravitas, he was also happy to laugh at himself, was great fun to work with and popular with other actors," said Ms LeConte, who is senior lecturer in acting at the Royal Welsh College of Music & Drama.
Entertainer Wyn Calvin said he was a friend of Madoc's for 50 years.
"He was a great conversationalist and was an extremely knowledgeable man. He was well-read and spoke a number of languages fluently," he added.
"He had a fine voice which was splendidly representative of the Welsh tone.
"The two things people will remember him for will be playing Lloyd-George and 'Don't tell him, Pike' from Dad's Army.
"How splendid to be remembered for something so serious and something so funny."
Madoc studied Languages at the Universities of Wales and Vienna, initially working as an interpreter.
He acted in the West End and with the Royal Shakespeare Company, his notable stage roles including Iago in Othello, Anthony in Anthony & Cleopatra and First Voice in Dylan Thomas' Under Milk Wood.
He appeared in films such as The Spy Who Came In From The Cold, The Quiller Memorandum and Operation Daybreak.
Madoc received an honorary doctorate from the University of Glamorgan, and was a fellow of the Royal Welsh College of Music & Drama.