It is perhaps ironic that for somebody who gained so much acclaim as a writer, Eric Sykes' most enduring work - The Plank - is a silent film. Sykes wrote his silent films more in camera than on paper, seeing the film already edited in his head and trying to make the shots match.

Lesser known is that The Plank first came to fruition in a 1964 episode of his sitcom Sykes And A..., having four variants in total. He wrote in his terrific autobiography If I Don't Write It, Nobody Else Will that "one good visual gag is worth a page of dialogue".

But Sykes was far more prolific than perhaps any other writer of the period. While the likes of Barrys' Cryer and Took wrote for an astonishing number of performers and comics, Sykes was part of a stable that turned scriptwriting into a bona-fide business, complete with their own office.

Associated London Scripts came about when Spike Milligan invited Sykes to share his office on Uxbridge Road in Shepherd's Bush in 1954. At that time, Sykes was writing Educating Archie for ventriloquist Peter Brough, and opined that they should in fact form a non-profit agency for writers. Milligan agreed and asked Galton & Simpson to join them. Their first secretary was Beryl Vertue, a woman who would go on to be a pioneering producer who, amongst many other things, found huge success selling sitcoms including Steptoe And Son and Till Death Us Do Part to America. (Anybody interested in the saga of ALS should read Graham McCann's excellent book Spike & Co..)

Sykes first broadcast on 14th September 1972, but was reborn from an earlier black-and-white series called Sykes And A..., which had aired from 1960 to 1965. Both formats share the same central set-up: Eric and Hattie Sykes (Hattie Jacques) are not just twins, they are identical twins (Sykes made them siblings to avoid the usual domestic dramas written into husband-and-wife scenarios) who live in an otherwise quiet street in the west London suburb of East Acton, and each episode sees Eric in various scrapes and mishaps, usually of his own making.

That first show was co-created by Johnny Speight, who wrote a number of episodes in the first series, as did Milligan and John Antrobus, but from the second series onwards, Sykes wrote alone. (Milligan and Sykes would team up again for the controversial Speight-scripted ITV sitcom Curry & Chips in 1969.) Out of the 59 episodes of Sykes And A..., only 32 exist in the BBC's archive, and to date only three episodes (Sykes And A Bath, Sykes And A Haunting and Sykes And An Ankle) have been released commercially (on VHS).

Such was the popularity of Sykes And A... that in 1961, Jacques and regular guest star Deryck Guyler co-starred in radio sitcom It's A Fair Cop, penned by John Junkin and Tony Hancock writer and Dalek creator Terry Nation. Officially, the BBC only holds one episode of this series, which was returned to them in their Treasure Hunt appeal for lost material in 2003, though three further off-air recordings are in the hands of private collectors.

Bridging the gap between the two versions was 1971 hybrid sitcom/sketch show Sykes And A Big, Big Show, in which Eric and Hattie link a series of sketches and musical numbers. Harold Snoad and Douglas Argent directed the 6-part series, only three of which still exist. Ian Wallace, Philip Gilbert, Tony Melody and Michael Knowles completed the ensemble cast.

Throughout, Eric's character was that of a fairly typical everyman - albeit perhaps even more petty and accident-prone. This stood in stark contrast to Hattie, who played a largely straight role to a tee. Although their personal relationship broke down in later years - to the extent that Jacques' family requested that Eric didn't attend her funeral - she is on record expressing "immense" respect for Eric because he didn't write gags about her appearance; rather he wrote to her strengths as a comic performer. In turn in an interview with the Radio Times in 1974, Sykes explained of Jacques that "Hattie is the best comic actress we have ever had. In all the years I've been writing for her, I've never made reference to her size, it's unnecessary".

Every comedy of this nature needs an authority figure to play against, and in the case of Sykes, which ran for 68 episodes from 1972 to 1979, this part was split between Richard Wattis as officious neighbour Charles Fulbright-Brown, and returning co-star Deryck Guyler, now in a more regular role as the affable local constable, Corky Turnbull, to whom Eric often turned for advice and, more often than not, help when his schemes went awry.

Sadly Wattis died in 1975, so Joy Harington was written in after the third series as new neighbour Melody Rumbelow. The final central 'character' took the form of Hat's beloved cuckoo clock, the tiny sculpted bird they christen Peter. Often chirping at exactly the wrong time, Eric engages him in regular antagonistic 'dialogue'.

Sykes' scriptwriting skill was perfectly exemplified in the iconic 1961 episode Sykes And A Bath. Later remade for the colour Sykes run - as were forty two other Sykes And A... scripts - the plot sees Eric get his big toe stuck in the tap while having a bath. He wrings every ounce of comedic potential out of the premise, from childishly playing with his toys to his escalating agitation at his immobile situation, rounding the episode off with the perfect comedy punchline after his extraction.

Where Sykes-penned scripts for The Goons were full of the imaginative imagery and surreal silliness the series was known for, Sykes was written more as a fully-fledged farce, a typical episode starting with a prosaic problem that gradually escalates. Indeed, by the time of the 1972 run Eric was well versed in the form, starring alongside Jimmy Edwards in Phillip King and Falkland L. Carey's stage hit Big Bad Mouse from 1966.

Edwards, in fact, would star in a colour revival of his own sitcom, Frank Muir and Denis Norden's Whack-O!, from 1971 to 1972; though that only lasted one series. As is sadly a recurring feature of shows from this era, only a handful of the black and white originals and a single colour episode survive in the BBC archive.

Coming from a variety background with an adoration of physical, visual humour, Eric Sykes built slapstick sequences into every episode he could. One prime example is when Eric and Hat find themselves handcuffed together in the episode Haunting. A scene in which Eric tries in vain to get a bite of his dinner while his hand is constantly pulled away by Hattie reaching for something is pure music hall. Then there's Boat, in which Eric's jealousy of Mr Brown's new boat sets off a chain of events that inevitably ends with him, and indeed everybody else, in the water.

Job, meanwhile, sees Eric join Hattie working in a factory. As Eric learns to use the machine to which he has been assigned, he and the other workers sync up into a rhythm whereby they pull the lever, bend down and kick their leg back - a ridiculously flamboyant sight. Sykes traded on pure vaudeville like this throughout its run; its comedy style a kinder, gentler counterpoint to the gritty kitchen sink drama realism against which the original format had been borne.

That isn't to say that Sykes was purely visual - far from it. Take this exchange, as Hattie fills out a crossword:

The cream of the comic crop popped up in the series over its seven year run, most notably Jacques' Carry On co-star Joan Sims in the recurring guest role of local baker Madge, plus Peter Sellers (Stranger), Pat Coombs (Uniform), Bill Pertwee (Protest), Ballard Berkeley (Engagement), Chic Murray and Bill Maynard (Journey), Bernard Bresslaw and John Bluthal (The Band), Hugh Paddick, Norman Beaton and Henry Woolf (Television Film) and John Junkin (Six Million Dollar Sykes).

In an unusually metatextual, postmodern script for the time, the 1979 finale The BBC Honours Sykes saw Eric and Hattie visit the BBC to be awarded a clock to celebrate twenty years on the air. Whilst there, they bump into Les Dawson, who reels off two minutes of his stage act before they go in to see the eccentric Head Of Light Entertainment, who has never heard of Eric or the sitcom.

Eric, it seemed, had a low view of this particular job, writing in his autobiography that "Ronnie Waldman was the first and last inspiring Head Of Light Entertainment, and those who followed in his footsteps were a disappointing bunch of trainee bureaucrats with a limited knowledge of what makes people laugh". Waldman had left the position in 1958. It's possible that Sykes could have continued, but the decision was taken to end it following the death of Jacques from a heart attack in October of that year. She was only 58.

Towards the end, Sykes began to remake several of his silent films in colour with Thames Television, including The Plank (with Arthur Lowe in the Tommy Cooper role) and Rhubarb Rhubarb!. New scripts followed, such as It's Your Move and Mr H Is Late, and he co-wrote and directed his final silent, The Big Freeze, in 1993.

The 1990s would bring about new endeavours for Eric, reaching a whole new generation and featuring in a No. 1 hit single. Few people realised it is Sykes' voice that announces "Teletubbies!" in the opening titles of the pre-school show and the official single release of the tune. (Entitled Teletubbies Say "Eh-oh", the single was number one in the charts for two weeks in December 1997.) He also voiced a lion in See Saw, an episode that was deemed so creepy for its pre-school audience it was banned in several countries and had to be re-edited.

Eric reunited with Johnny Speight in 1989 to star in golfing sitcom The Nineteenth Hole, and memorably played Stan's father in the Trouble episode of Victoria Wood's wonderful dinnerladies a decade later. His final sitcom appearances include playing the titular character in Visiting Uncle Dick, a Comic Relief sketch David Renwick wrote in 2001 as a send-off to One Foot In The Grave; My Family episode Four Affairs And A Funeral; and Last Of The Summer Wine instalment The Second Stag Night Of Doggy Wilkinson (both 2007).

In 1992, almost thirteen years after the end of his sitcom, Sykes was honoured with a lifetime achievement award from The Writers' Guild Of Great Britain. The footage of the event is well worth a watch, as Spike Milligan surprises Sykes while in the middle of a performance of Speight's play The 19th Hole at the Richmond Theatre.

Perhaps due to the gentle nature of Eric's writing, perhaps due to the comedy-establishment-overturning 'alternative comedy' wave that epitomised the decade that followed its end, Sykes never quite made it into the pantheon of widely-recognised sitcom greats, in which it more than deserves a place. Now that the series has been released on DVD in its entirety, it can finally be reappraised as the classic comedy it is.