The BBC's Welsh language soap opera Pobol y Cwm is celebrating its 40th anniversary.
Since 16 October 1974, the award-winning drama series has followed the residents of Cwmderi, a fictional village in west Wales.
The soap is made by BBC Wales and broadcast on S4C five nights a week.
BBC Cymru Wales director Rhodri Talfan Davies said he was proud of the programme.
"Since it began, Pobol y Cwm has been right at the beating heart of Welsh language television, and consistently S4C's most popular weeknight programme," he said.
"Pobol y Cwm is an exacting and complex production, shooting about 18 scenes in studio each and every day - an extraordinary feat.
"It moves confidently with the times and has never been afraid to tackle the tougher stories."
Pobol y Cwm was initially broadcast on BBC Wales TV before the arrival of the Welsh language channel S4C in 1982.
For a short period it was also shown on BBC Two across the UK with English subtitles, while viewers in the Netherlands also watched with Dutch subtitles in 1991.
The programme currently employs a cast and crew of about 80 people who are based at the BBC's Roath Lock drama studios.
While the series is currently broadcast five nights a week, the number of episodes will be reduced to four nights a week in the new year because of budget cuts at S4C.
Terry Dyddgen Jones, an experienced director who has worked on Pobol y Cwm as well as other soap operas including Coronation Street, EastEnders and Hollyoaks, said Pobol y Cwm was a good reflection of Welsh life.
"It's often said that drama holds a mirror up to life, and I think that Pobol y Cwm has held up a mirror to Welsh society and Welsh life, and the Welsh way of living for the last 40 years.
"Not only does the programme exist to serve Wales but there is an awareness of Pobol y Cwm outside Wales as well, because when I work outside Wales and people say 'What are you coming back to do?' and I'll say 'I'm working on Pobol y Cwm,' it is a brand they are aware of."
As part of the 40th anniversary episodes to air this week, it has emerged that one of the programme's most popular characters will soon be leaving Cwmderi after spending 40 years in the village.
Meic Pierce revealed in Tuesday night's episode that he has terminal cancer. The actor who plays Meic, Gareth Lewis, has decided to retire after playing the part for most of his adult life.
"I just decided that I thought 40 years of being associated with this series was quite enough really, for myself and for the audience at home as well.
"I joined the cast in January 1975 and I thought it'd be quite nice to finish around January or February 2015 - so completing a period of 40 years associated with the programme," he said.
Pobol y Cwm is broadcast Monday to Friday at 20:00 BST on S4C.