We may take for granted now that the arts in this country are prone to relatively little external censorship. However, this has only really been the case since 1968, when the Theatre Act was passed by government to allow for freer artistic expression in British playhouses.

Before this time all play-scripts destined for production were required to be sent to the Lord Chamberlain for his approval. Not technically an instrument of the government but of the monarchy, the Lord Chamberlain's 'readers' had the power to fine, censor or ban outright any play that they deemed unsuitable for public performance.

Famously, the censorship encompassed outlawing nudity, swearing and anything regarded as 'promoting' homosexuality or homosexual acts.
In 1968 however, bowing to much public and artistic pressure, the matter was brought before the House of Lords and the Theatre Act of 1968 was enforced abolishing theatrical censorship.

Key figures in proceedings were the playwright John Osborne and the outspoken critic Kenneth Tynan who both gave evidence at the hearing.

The liberation of theatre came at a time synonymous with cultural revolution. The 1960s, a decade famed for its radical uprooting of social conventions, had already legalised homosexuality and begun to alter the way it viewed casual sex, racial inequality and recreational drug use. What's more, many young playwrights (often grouped together under the banner "The Angry Young Men") where producing thought-provoking works that tested and scrutinised the boundaries of what could and could not pass for 'legitimate' theatre. Great writers like John Osborne, whose play 'Look Back in Anger' is often cited as the quintessential work of the movement, and Harold Pinter were quickly amassing reputations as challenging, and even dangerous, theatrical practitioners.

Of course, in such a turbulent political and cultural climate theatre censorship became completely untenable. The Theatre Act of 1968 was brought in and the American musical Hair opened in the West End just 24 hours later. Featuring scenes containing nudity, drug taking and boasting a stringent anti-Vietnam War message, the show was a complete break from the repression of theatre censorship that preceded it.

Since then, it might be argued, that theatre has 'gone the other way' and now shows little regard for staging any material that might offend. The comedian Peter Cook once quipped: "I don't want to see plays about rape, sodomy and domestic abuse; I can get all that at home." Though, of course, Cook was taking a fairly surrealist swipe at the prevailing middle-class (often hypocritical) sensibilities, perhaps there might be a germ of truth in what he's saying. Namely, just because theatre can show things like rape, sodomy and domestic abuse, should it?

The answer, it would seem, is entirely dictated by an individual play and the motivations and intentions that it possesses. Gratuitously exploiting a subject is not the same as fearlessly addressing it.

A more pressing consideration might be concerned with taking another look at the idea that opened this article, that theatre is prone to little external censorship. Though now there are no legislative restrictions in place to curtail playwrights' artistic vision, other factors may seem to limit theatre in ways not altogether obvious. For example, Margaret Thatcher's government cut public funding to the arts dramatically in the 1980s. Such a financial stranglehold might not have directly censored dramatic material, but it certainly forced many playhouses to stage fewer new plays and even close outright.

In more recent times, when the Birmingham Repertory Theatre staged Behtzi in 2004, the theatre was the scene of angry rioting by a portion of the sikh community that felt the play mocked their faith.

Whether theatre and the arts can ever be totally free to express itself in the way it chooses is debatable, the debt owed to those that ended the formal censorship however is not. Quite simply, without the efforts of people like Osborne and Tynan, the West End might not be the respected home of expressive theatre that it is today.