The exhibition, The Golden Generation, opening today at the British Library is the culmination of the Theatre Archive Project, a University of Sheffield and British Library collaboration.

The five-year project, funded by the Arts and Humanities Research Council (AHRC), has helped shed new light on British theatre between the end of the Second World War in 1945 and the abolition of theatre censorship in 1968.

This period was a time of social transformation and heralded the emergence of influential theatre practitioners including Harold Pinter, John Osborne, Alan Ayckbourn and Joe Orton, and confirmed talents such as Laurence Olivier and Terrence Rattigan.

As part of the project, people who visited or worked in post-war theatre were encouraged to share their recollections of British theatre for the first time.

Interviewees featured in the exhibition will include Murray Melvin, who played Geof in the stage and film versions of A Taste of Honey; Michael Seymour, a stage electrician at the Royal Court who looked down on the premiere of The Entertainer from high in the flies and playwright Peter Nichols trying to remember when the censors permitted breasts to be bared on stage.

These interviews and more will be available at sound points around the exhibition and will be paired with archival material selected from the British Library's modern theatre collections.

Highlights from the archives include the only surviving scripts of the first two plays of John Osborne, The Devil Inside Him and Personal Enemy, the former written nine years before the 1956 premiere of 'Look Back in Anger'.

This is the first time that the scripts will be publicly displayed and both items demonstrate the interference of the Lord Chamberlain's theatre censors.

The portrayal of homosexual characters was the subject that most worried the Lord Chamberlain in the post-war years. Attempts to prohibit representations of homosexuality led some writers to instinctual self-censorship - as can be seen in a handwritten script of Terrence Rattigan's Separate Tables.

Other exhibits include a handwritten draft of The Entertainer, the script sent to Olivier by John Osborne after writing an attack on Olivier in the London Evening Standard. The script will be displayed alongside 'disgusted' fan letters, complaining that Olivier – matinee idol and King of the West End - should play a lecherous old roué.

A handwritten draft of Harold Pinter's The Homecoming will also be displayed, accompanied by letters to Pinter from playwrights Noel Coward and Samuel Beckett. Both writers - representing the old guard and radical new ideas, respectively - enthuse about the play in their own distinctive styles.

The Theatre Archive Project has also recovered several hundred missing scripts performed after 1968 in theatres across the country.

As a result of the 1968 Theatres Act, which ended the Lord Chamberlain's power to pre-censor theatre, many new scripts were never deposited in the British Library's archives.

By asking all of the theatres in Great Britain for a list of new plays performed since 1968 and comparing these to the holdings at the British Library, the project team were able to identify the missing plays. Between September 2004 and April 2005 over 1,000 missing scripts were identified from fewer than 100 theatres.

To date, nearly 300 of these play scripts have been recovered.

Professor Dominic Shellard, Project Leader and Pro-Vice-Chancellor for External Affairs at the University of Sheffield, said:

"The unique collaboration between the University of Sheffield and the British Library, and generously funded by the AHRC, has helped to re-evaluate the golden period of British theatre between 1945 and 1968. No-one can ever now claim that British theatre 'began' on 8 May 1956 with the premiere of Look Back in Anger.

"Such has been the project's success that it will carry on interviewing people with direct recollections of the drama of this time - adding to the over 1 million words of transcripts already collected."