The legendary comedy duo's Christmas Specials began in 1969, but the phenomenon exploded in 1971 when the first, lavish, extended Christmas production was broadcast.

Shirley Bassey sang in hobnail boots; Glenda Jackson was serenaded by an assortment of BBC Presenters and the Andre Previn sketch stole the show. From then on, every subsequent year demanded new stars and great sketches. Diana Rigg played Nell Gwynne, Elton John was sent the wrong way round Television Centre, Vanessa Redgrave starred in a Latin-American extravaganza and a leggy Angela Rippon emerged from behind the news desk to perform a legendary dance routine.

In their last year at the BBC, the show reached its peak as a record 28 million people tuned in to see a chorus line of newsreaders acrobatically dance and sing 'There Ain't Nothing Like a Dame', Penelope Keith climb awkwardly from an unfinished stairway and an unexpected return for Elton John.