Harriet Walter in Henry IV, 2014

At first, it almost sounds like a pantomime: the tyrannical rule of Julius Caesar embodied by a sadistic Frances Barber; the regal authority of Henry IV assumed by a masculine Harriet Walter; the Oedipal disgust of Hamlet tormenting a princely Maxine Peake. And naturally so, the concept of female actresses taking on roles written for men might sound comedic, if dubiously alternative. But unlike the much-loved panto dame, or Shakespeare’s cross-dressing heroines, this practice in gender-swapping on the stage is not for frivolous entertainment. It is gaining momentum as an widespread theatrical culture, and one with an invigorating, transformative power for plays.

The recent buzz surrounding cross-gender casting is neither sudden nor new. Kathryn Hunter famously tackled King Lear in 1997, Fiona Shaw played Richard II in 1997, and even as far back as 1899, Sarah Bernhardt played Hamlet. Reviews varied, questioning the validity of the concept. ‘Old Mrs Lear is not every inch a king’ one headline ran, in an article which brought the ambitious experiment back down to size.

However, since 2012, when the Donmar Warehouse began its trilogy of all-female Shakespeare plays, these once-novelty cross-gender productions have gathered (and indeed merited) increasing artistic respect. Directed by Phyllida Lloyd, the first play, Julius Caesar, relocated the action of Ancient Rome to a women’s prison; the second, Henry IV, triumphantly followed this mould in 2014, and the final, yet unannounced instalment is due to be staged in 2016.

Maxine Peake in Hamlet, 2014

The phrase ‘feminist agenda’ might cause some eye-rolling among cynics, but Lloyd’s project is borne out of a valid frustration: that all of the major roles in theatre – particularly those of Greek tragedy and the Renaissance, when women could not perform on stage – are predominantly written for men. Actors’ union Equity conducted research into subsidised theatres and found that, on average, male roles outnumbered female roles by an average of two to one.

Yet the issue is less the lack of female roles available, so much as their relative insignificance in plays that are so male-centric. Lloyd specifically describes wanting to ‘liberate some of these fantastic actresses from the romantic and domestic sphere in classical work’. Indeed, most of the complex villains and tragic protagonists that will mark a professional milestone for any actor are all male. The female characters, meanwhile, serve as submissive and peripheral tag-alongs.

On playing Hamlet, Maxine Peake remarks ‘it was quite enlightening as an actress, being in a part where you are the centre of the play and everything revolves around you… That’s not normally the situation we are in.’ For however talented these rightly-called ‘fantastic actresses’ may be, their potential is often inhibited by the roles available to them; even the stronger heroines – Portia, Gertrude, Lady Macbeth – must perish by marriage or death for the sake of patriarchy and male heroism.

Julius Caesar, 2012

Honourable intentions aside, the actual value of cross-gender casting has been naturally divisive. Ahead of the Donmar’s production of Henry IV, old RSC stalwart Joss Ackland, who has played Falstaff twice, argued: ‘You can only play something you’ve experienced or observed… That’s why I don’t really get the all-female approach. As I see it, a woman could no more play Falstaff than I could play Ophelia.’

Contrary to this opinion, actress Ashley McGuire was lauded as ‘not just a good but a magnificent Falstaff… A one-person vindication of the all-female approach’. But, more importantly, Ackland seems to have forgotten that the first person who played Ophelia – indeed any female character – was a man. And if this old-fashioned, all-male approach is still alive today, with Edward Hall’s touring Propeller company aiming to recreate the authenticity of Shakespeare’s plays as they were initially performed, then a parallel all-female approach is well overdue.

So if the quality of female characters is the problem, why not just create new parts that are more demanding? The answer – because, as Lloyd adds, this is not just about a 21st-century push for equality: the plays were ‘also an experiment to see what happens when you play these old, very familiar scores with new instruments and suddenly hear new things’.

It is in this artistic initiative that the strength of cross-gender performance is most apparent. These canonical works are so deep-seated in our cultural heritage – schools teach them, writers rely on them, artists return to them – that to see them so easily inverted has the potential for all kinds of enlightenment. A change of sex brings a change of perspective: just moments into the Donmar’s Henry IV, our social assumptions are distorted, human relationships ring more violent, and most strikingly, gender boundaries become blurred. To hear a female Hamlet proclaim ‘frailty, thy name is woman’, or see the themes of honour and friendship reverberating amongst the inmates of a female prison, breathes fresh life into dusty words.

Ashley McGuire in Henry IV, 2014

Needless to say, the implications of this are exciting, but they shouldn’t start and end with women. There’s no reason why male actors shouldn’t step into the shoes of modern heroines. Who can imagine Tom Hiddleston as a hysterical Blanche DuBois, or James McAvoy as an emancipated Nora Helmer? (Well, I can’t, but they sound no more ridiculous than the transitions we’ve already had).

In June 2015, David Suchet will star as Lady Bracknell in Oscar Wilde’s The Importance of Being Earnest, the latest in the a recent line of male actors to take on the matriarch. Michael Fitzgerald, who played her in 2005, claimed: ‘A man can play Lady Bracknell because she is sexless’. Indeed, perhaps it is that every other character on stage is fundamentally ‘sexless’ as well – the fluidity of interpretation is all.

The purpose of theatre is not to hold up a mirror to reality and reflect it literally. It should re-evaluate, explore and provoke in a way that is truthful but interpretative. The all-female or cross-gender approach does that on paper; but to hear the words of heroes and the actions of men appropriated by women for the stage holds a kind of revolutionary power. And, let’s be frank – in theatre, that’s rare.