No, it wasn't nearly as big a step as getting the vote in 1918. But it was surely a step in the right direction when, at the Restoration in 1660, women's roles were at long last given to women rather than to boy transvestites. Playhouse Creatures, by April de Angelis, shows how, for these pioneering professional actresses, the new social and artistic freedoms came with distinct drawbacks in the shape of fickle, exploitative aristocratic patrons, audiences bent on treating female "thesps" as whores, and a men-only policy on financial "sharing" in the companies.

The piece could have been a grim whine or a thinly disguised Open University programme. In Lynne Parker's zestful production at the Old Vic, it emerges as a wonderfully funny and gutsy evocation of life on-stage and backstage in the attiring-room which, at the start, is conjured up from the past by Liz Smith's timeless - and hilariously timed - crone of a dresser-cum- stage manager. Connoisseurs of Green Room bitching and of hoicked-up, ample bosoms will get as much out of this show as toilers in the field of women's studies.

Sharp and witty, Ms de Angelis's last play, The Positive Hour, was prepared to confront uncomfortable truths about the sometimes messy, divisive effects of feminism on female fortysomethings. Likewise, there are good moments in this look at a pre-feminist society when we shared victimhood signally failing to unionise the actresses. When Mrs Farley (Saskia Reeves) faces professional ruin because of pregnancy, her colleagues are willing to help out by giving her a broach-pin abortion. But when she can't go through with this, they recoil superstitiously from buying the fancy petticoat she won't be needing so much in her future career as a vagrant prostitute.

The production is a practical as well as theoretical celebration of the actress's art. Sheila Gish is in brilliant form as Mrs Betterton, the grande dame eventually pushed aside by nubile competitive juniors. Demonstrating how to convey emotions by tilting that flat pugnacious face of hers to different clock-hand positions ("Shame at 20 to seven. Despair at five past 12"), she's the hard-bitten, pedantic technician taken to gloriously batty degrees. But she's authentically thrilling when she performs Lady Macbeth's sleep-walking scene in the in-period heroic manner. And hearing her talk with a sepulchrally fervent nostalgia of the old days when she used to sneak herself on stage in powerful male parts like Iago and Hal, you get a tremendous sense of the frustrating inequalities in the repertoire that arguably persist after 300 years of women in theatre.

In the second half, the proceedings drift a bit, despite the fact that the agenda also becomes more obvious. We see, with Ali White's Mrs Barry, the emergence of a tougher new breed of actress, intent on taking control of their careers. There's the suggestion that playwrights, like Stephen Noonan's Otway, are beginning to respond to female threats of non-co-operation if roles don't precisely suit the performer's requirements. But by the time he finishes a drama tailor-made for Rachel Power's Mrs Marshall, she has had to flee from the wrath and the accusations of witchcraft put about by her former protector, the Earl of Oxford.

My own face tilted to the 20 past 10 of scepticism at certain points (over the central metaphor, for example, you want to ask: were no male bears ever cruelly baited?) but, for the most part, it was positioned at the "heavenly abandonment" of six o'clock.

In rep at the Old Vic, London SE1 to 6 Oct (0171-928 7616)