All our yesterdays, composed of clips, cuts and Charlie Chaplin out-takes

The National Film and Television Archive has just completed a five-year, £12m cataloguing project. Louise Jury explores the unseen footage that was uncovered in the process

For the past 100 years, the history of Britain and its culture has been told through the moving image. And from newsreels to advertisements, television shows to movies, the British Film Institute's National Film and Television Archive has everything that has been recorded on film or video for more than a century.

Yet until recently, the archive could not be sure what lay in the vaults at their headquarters in Berkhamsted, Hertfordshire. A flurry of well-meaning donations had left it with 60 million feet of previously unexamined footage.

Now, thanks to a five-year project costing £12m, 80 experts have catalogued and conserved the archive. They have uncovered a valuable and quirky treasure trove of film, including unseen footage of Charlie Chaplin films, public information newsreels and a pilot of a David Jason comedy.

All will be available in the 1,500 libraries, schools and colleges which have signed up to screenonline, the BFI's internet library, or from the BFI library itself to students for a small fee. Many will be featured in future seasons of film and television at the BFI's film centre, the National Film Theatre, in London.

The results of the exercise were revealed yesterday by film director Anthony Minghella, the chairman of the British Film Institute, and Liz Forgan, of the Heritage Lottery Fund, which provided most of the funding.

Some of the highlights that have now been safeguarded for future generations were screened yesterday under the banner "An Archive for the 21st Century". There were slices of film history in out-takes from one of Chaplin's early masterpieces, The Pawnbroker, made in 1916, and a restored version of Laurence Olivier in a 1937 film version of As You Like It edited by the director David Lean with music by William Walton.

Vintage children's television programmes such as Rainbow and Sooty have been saved alongside three different versions of Guinness adverts from the 1960s and 1970s, each using the same script but cast with white, Asian and black actors for markets in Europe, Asia and Africa.

An hilarious full-length film about nudists made in 1958 has the (unexplained) support of a fully clothed Duke of Bedford. In a striking London Weekend Television documentary dating from 1971, the gay black American writer James Baldwin lashes out at the white TV crew attempting to interview him in Paris.

"My work will speak for itself or it won't," Baldwin said. "But I'm a black man in the middle of this century and I speak to that ... I'm one of the very few dark people in the world to have a voice."

A pilot episode of a David Jason comedy called Lucky Fella made by London Weekend Television in 1975 but never broadcast has now been copied and catalogued for all to see.

And alongside the lighter moments, there is documentary and newsreel footage of historical moments that include funerals and floods, strikes and freak weather, state visits and party political broadcasts. Nearly the entire run of Topical Budget newsreels from 1911 to 1931 are in the . Later newsreels include a rousing war-time broadcast from 1943 in which a plum-in-mouth announcer wonders whether the Germans "in their black hearts" wished that they had "never started this carnival of slaughter".

There are also examples of the Mining Review broadcasts which were made between 1947 and 1983 specifically for screening in Britain's mining communities. One shown yesterday featured a Welsh mining family who had won a family holiday to a Butlin's holiday camp.

On arrival, they were greeted by Billy Butlin himself and revelled in the excitement of snooker, horse-riding and a holiday princess competition which resembled a wrestling match as unwilling contestants were manhandled into taking part.

There are also countless television interviews such as a 1979 recording of an interview with the writer, Arthur C Clarke, who with unnerving prescience predicted the widespread use in the future of something like the internet.

"Once you see this material, it is self-evident why it should be preserved," Mr Minghella said after watching the 40-minute taster yesterday. "It is a fantastic vindication of the archive - you realise what could be lost. This is the most pungent record we've ever had for understanding our history. It's so evocative."

He cited one example to prove his point - a home movie of the Prince of Wales, later Edward VIII, visiting Berkhamsted in 1935, where he is greeted by boy scouts and veterans of the Boer and First World Wars, marching proudly with their medals. "Just looking at that, you see the manners and mechanisms and culture of a period," Mr Minghella said. "The thing that is overwhelming is the diversity of material. It's not just fiction, it's not just documentary, it's not just actuality. It is a complete social record that is crucial as a means of understanding ourselves and our history."

The initiative, which was three-quarters funded by the Heritage Lottery Fund with extra support from the late John Paul Getty, was instituted five years ago after a spate of significant donations had created a sizeable backlog in cataloguing.

The donations included collections of the original negatives of films held by several film laboratories, the home-movie collections of figures including the writer-producer Emeric Pressberger and the director John Schlesinger, the Public Record Office's collection of government information films and the advertising collections from Guinness, United Distillers and John Player cigarettes.

The archive's annual budget of around £3.2 million, which comes out of the £14.5 million the BFI receives from the Film Council to carry out its role in educating the public about film, was simply not big enough to tackle the load.

But the Heritage Lottery Fund agreed to step in and help. Up to 80 extra staff were recruited, and in some cases, trained, for the work of examining the millions and millions of feet of film. As a result, more than 85,000 titles were catalogued and indexed and more than 83,000 master and viewing copies of films, television shows and other broadcasts have been added to the BFI's collection.

One of the most important jobs was transferring 35,000 videotapes in a Quadruplex two-inch format, once standard in the TV industry but now obsolete, to a digital form.

Liz Forgan said yesterday that the ability to capture the sights and sounds of our times in real sound was one of the greatest developments of the 20th and 21st centuries. "Moving pictures - whether of fact or fiction - have a magnetic power over the human mind and memory that is special and unique."

Describing "An Archive for the 21st Century" as a triumph, Ms Forgan said the project had done exactly what the fund was set up to do - to preserve the treasures handed down from the past and make them available to as many people as possible. "It will reach out to new audiences, enthralled by the great movies, wonderful television footage and classic documentaries," she said.

"It will train a new generation of staff in the demanding skills of preservation and restoration. And it will do honour to the work of great filmmakers, directors and recorders of history."

The exercise has been timely. The situation at the archive was raised with some concern by MPs on the Public Accounts Committee last year, who feared that some of the BFI's most volatile film on nitrate was not being stored safely.

Although the BFI has always insisted that the archive was being properly looked after, Ruth Kelly, its registrar, admitted yesterday that material had been coming in faster than they were able to deal with it before this project got underway. "While it was sitting there unlooked at, we could never be sure that the nation's heritage was safe," she said. "But this has enabled us to get through the backlog of material dumped on us. There's still more to do, but we're very much on top of it now, whereas before we could only look and ponder. This is a real step-change in the level of material that is accessible."

Anthony Minghella stressed that both he and Amanda Nevill, the BFI's director, had implemented a strategic review to make sure the archive was on a sound footing for the future. "The archive is overwhelming and will always be overwhelming because its ambition is to both preserve and provide access to a huge collection of moving image documents," he said.

"That will always be a struggle, a struggle compounded by the fact that film is hard to store, film is hard to interpret - because when you pull a bit of film out, you have to have a method of viewing it - and it's bulky. There are all the problems of storing books and then some. But even so, it is something to be celebrated. The moving image is a whole way of looking at the world and interpreting it."