A revival of hit sitcom Are You Being Served? was watched by more than 5 million people last night.

Initial overnight ratings - a lower-end estimate of the number of viewers of a programme - show 5,039,000 people watched the one-off episode on BBC One at 9pm; a 24.5% share of the entire television audience. It was immediately followed by a new take on classic Ronnie Barker sitcom Porridge, which attracted 4,395,000 viewers according to the same overnight figures.

The figures make Are You Being Served? the 10th most-watched British comedy of 2016, beaten only by four episodes of Still Open All Hours; two editions of Mrs Brown's Boys; the festive special Billionaire Boy; and one episode each of Michael McIntyre's Big Show and Benidorm.

Audience numbers for both programmes will grow significantly to a consolidated figure in coming weeks, once iPlayer views and recorded viewings are taken into account.

A range of contemporary comedy acting talent recreated the characters and performances of the globally popular original Are You Being Served? cast in an episode set in 1988, just 3 years after the 1985 finale of the original series.

Written by Benidorm scribe Derren Litten, the programme starred Sherrie Hewson as Mollie Sugden's Mrs Slocombe; Jason Watkins as John Inman's Mr Humphries; Roy Barraclough as Arthur Brough's Mr Grainger; Niky Wardley as Wendy Richard's Miss Brahms; John Challis as Frank Thornton's Captain Peacock; Justin Edwards as Nicholas Smith's Mr Rumbold; and Arthur Smith as Arthur English's caretaker, Mr Harman.

New characters Mr Conway (Kayode Ewumi), Young Mr Grace (Mathew Horne) and secretary Miss Croft (Jorgie Porter) were also introduced.

The new Porridge special was written by the original series creators, Dick Clement and Ian Le Frenais, and saw Norman Stanley Fletcher's grandson, also known as Fletch, in prison for cyber crimes.

Kevin Bishop took on the starring role of Fletch, with Dave Hill as cell-mate Joe; Mark Bonnar as mealy-mouthed warder Meekie; and Dominic Coleman as the more genteel Mr Braithwaite. Other cast members included Colin Salmon, Ricky Grover, Ralph Ineson, and Martin Trenaman as Fletch's father, Raymond - Barker's Fletch's son; a role originally inhabited by Nicholas Lyndhurst.

The episode becomes the 22nd most-watched British comedy of 2016 to date, after those listed above, plus additional episodes of Benidorm; Birds Of A Feather; Have I Got News For You; Michael McIntyre's Big Show; and one edition of Peter Kay's Comedy Shuffle.

However, both comedies were beaten by ITV's feature-length opening episode of new period drama Victoria, starring Jenna Coleman as the young Queen Victoria.

The two sitcom specials were broadcast as the opening episodes of Landmark Sitcom Season, a 3-week run of programming celebrating the long history of BBC television sitcoms. Whilst not formally pilots for potential series, BBC comedy boss Shane Allen has made clear that full series could be ordered if the episodes prove popular with audiences.

The season will also see a new special of 1990s classic Goodnight Sweetheart, starring Nicholas Lyndhurst as time-traveller Gary Sparrow; and a Keeping Up Appearances prequel, Young Hyacinth, featuring Kerry Howard as Hyacinth in her twenties.

News of the high ratings come as the small number of mainstream, family-friendly - and in particular, studio audience - comedies are proving enduringly popular, despite near-universal critical condemnation. Not Going Out is to become the BBC's longest-running present sitcom shortly with an eighth series in production, whilst Still Open All Hours, Birds Of A Feather and Mrs Brown's Boys also provide consistently high ratings and huge popularity amongst the public.

Meanwhile, repeats of Dad's Army on BBC Two continue to prove to be the channel's most-watched programme each Saturday, save for any major sporting events, and repeats of Mrs Brown's Boys on BBC One continue to see audiences in excess of 3 million viewers.

However, despite the small number of mainstream, family-friendly comedies on television, their existence and success was criticised last week at the Edinburgh International Television Festival.

Radio Times and The Guardian report stand-up comedian Frankie Boyle as having commented: "There's an air where you wouldn't know alternative comedy had happened. Most of the comedy is observational, most of the big shows are variety shows and most of the sitcoms are family-friendly. I think it's hit a bit of a stale patch."

Of the 870 television comedy episodes broadcast in 2016 to date, fewer than 80 have attracted more than 3 million viewers. The average rating of all programmes is under 700,000 viewers, with only 380 programmes registering high enough audiences to appear at all in the audience data British Comedy Guide receives.