It has taken John Wilmot 15 years to go from the plain brown covers of erotica presses to the respectable black and yellow of Penguin classics. So reckons director Max Stafford-Clark whose theatre group Out of Joint brings a double portrait of Wilmot, second earl of Rochester (1647-1680), to London’s Royal Court Theatre.

The diptych can be seen either way round but Stafford-Clark points out that the view from Wilmot’s own day, George Etherege’s The Man of Mode is picked up eight years on in Stephen Jeffreys’s new play about Rochester’s milieu, The Libertine.

True, this assumes the frequently made assertion that Etherege’s rake Dorimant is indeed a portrait of Rochester. Dorimant-Rochester is played in identical costumes by David Westhead with a cynical charm, undercut in The Libertine by snarling warnings against finding him endearing.

There is, Stafford-Clark says, a direct line from Restoration comedy to Coward, Rattigan and Ayckbourn. But that continuity was far from certain at the time. “Elizabethan theatre had been cut off by the 20 years’ interregnum. There was a reinvention of theatre, when it was not known to be leading to Sheridan and Goldsmith” - let alone beyond.

After initial popularity, Man of Mode lay unperformed from 1725 to 1971. Meanwhile Restoration comedy as a live genre had been rediscovered by Coward’s generation in the 1930s and dressed up by them as drawing-room comedies, exercises in wit and elegance with gowns and beauty spots. That is a far cry from Stafford-Clark’s work. A self-styled theatre puritan, his rehearsals involve company research into the society that produced a play and intensive examination, almost phrase by phrase, of each character’s motivation and the ways they try to influence others. Even in an interview, he is darting round the room, searching out a picture, diving into Rochester’s poems or acting out a scene to illustrate the politically hugely incorrect, but very useful, rehearsal technique of handling the text in the style of gay New York hairdressers. “Gossip is peripheral in our society; to these characters it was central. The rehearsal brought out the relish of language, for gossip and scandal.”

Rochester was Stafford-Clark’s starting point, Man of Mode originally just one of several contenders to accompany Jeffreys’ play. “There’s no doubt Rochester would have been an extraordinary person to have met. As we all are, he was a prisoner of the morality and perceptions of his day.” A prisoner who fretted at his chains and one who had the breadth of imagination to put alongside predictable enough denigration of women, “the idlest part of God’s creation”, the female voice wondering at women’s submission to foolish men.

If the rake beats at the boundaries, the fop tries to find a place within them. Sir Fopling Flutter is the clearest candidate for frills and flummery. Not with Stafford-Clark. “Fopling has an objective, to be best friends with Dorimant, who pretends he is.” A sign of Sir Fopling’s shallowness or an existential emptiness? The director inclines to the latter; he believes, alien though the Fop as such is to modern minds, there is no loss of laughs through playing him for real. “There is a darkness in these plays. I claim I’m responding to the text. If you fop him up, you evade the central action. ”

He contrasts the Etherege with the Wycherly play he directed for the RSC. “The Country Wife is comedy tending to farce; Man of Mode is comedy tending to drama.” Meaning? “There are witty lines in Etherege but no wholly funny scenes such as the china scene in Country Wife.”

It is unsurprising given the social direction of both Stafford-Clark’s old Joint Stock theatre company and the Royal Court, to find him relating Man of Mode very precisely to its day - 1675. There were, he reckons, only a few years when such a cynical, sexually frank piece could have been staged. Ten years earlier there was still the afterglow of Charles II’s Restoration and hopes for healing; later attacks on the profanity of the stage took their toll.

Then came Blenheim - “the greatest land victory since Agincourt” - and no room for cynicism.

Though he accepts the achievements of physical theatre, Stafford-Clark is wedded closely to the word. Dialogue in Man of Mode is “not as people spoke, but as they wanted to be thought to have spoken”; he praises its balance, wit and muscularity, “the way language drives thought forward” and cites Howard Barker as an equivalent modern stylist.

Restoration Comedy habitually reached the happy end of marriage but (another visit to the bookshelf) Stafford-Clark points out that only a couple of pages from the end Dorimant accompanies the resolution of marriage to Harriet with a promised assignation with Belinda.

Furthermore he leaps on her quandary - she knows she shouldn’t but she wants to - to suggest there was more talk about sex than activity (Belinda begins the play as a virgin). So we are back to gossip and scandal in a world where sexual pleasure (or its anticipation) was the business of the day as well as night.

The Libertine, besides its picture of Rochester, qualifies our view of Harriet by casting her as the deceived wife Elizabeth Malet. Other casting enriches the view of Etherege’s characters - Mrs Loveit becoming Elizabeth Barry, the actress who created her and, deliciously, Dorimant’s snide sidekick Medley turning up as Etherege himself.

Each play runs approximately two hours 45 minutes including interval.

Details 071-730 1745