Presenter Michael Aspel has quit long-running TV show This Is Your Life, amid uncertainty about the programme's future.
Aspel with his red book
Aspel was recording a programme with pop music mogul Simon Cowell when he announced he was leaving.
"I have been hosting the programme for 15 years and I am closing the book for the last time this evening," he told the audience at Teddington Studios, south-west London, on Monday .
Based on a US format, the show is one of the longest-running on British television, having first started on the BBC in 1955 with Eamonn Andrews.
The programme's host - carrying its trademark big red book - surprises a celebrity, then takes them back to a studio for a discussion about their life, where they are reunited with old colleagues and family members.
It was axed in 1964, but Andrews fronted a revival on ITV in 1969, made by Thames Television.
The show clocked up huge ratings in the 1970s and 1980s, pulling in up to 20 million viewers.
It was thought the programme would end after Eamonn Andrews died in 1987, but it continued with Aspel as host.
However, the show fell out of favour with ITV in the early 1990s, and Thames took it to BBC One in 1994.
Eamonn Andrews with 1955 guest Captain CB Fry
Reports had suggested the programme was under threat, because of falling ratings and the reported refusal of younger celebrities to appear on the show.
But the BBC said it had merely asked Thames to refresh the format.
Aspel, 70, is one of the UK's best-known broadcasters, having begun his career as a radio actor for the BBC in Cardiff in 1954.
After that he became a newsreader for the BBC, and went on to host a variety of programmes for both the BBC and ITV, as well as on radio.
He was awarded the OBE in 1993 for services to broadcasting and was voted into the Royal Television Society's hall of fame for outstanding service to the medium.
BBC One controller Lorraine Heggessey said: "Michael Aspel has gone a fantastic job and created many memorable programmes with his red book.
"He continues an important role on BBC One as the presenter of one of our longest running and most successful programmes, the Antiques Roadshow."