Edna O'Brien: 'The anger of heaven is nothing to the anger of men'

The Irish writer Edna O'Brien, 70, is well known for her early novels which caused a huge storm in her homeland in the Sixties. Then last year, In the Forest – her fictionalised novel about a multiple murder in rural Ireland – was met with astonishing personal attacks in the nation's media. Among other things, she was called a "vainglorious idiot" and "a moral leper". So it is interesting that the latest project for O'Brien – who now lives in London – is an adaptation of the Greek drama Iphigenia of Aulis by Euripides, a writer who was born and died in exile and was an outcast of Athenian literary life.

When I meet O'Brien during rehearsals for the play at Sheffield's Crucible Theatre I ask her if she sees any parallels. She ponders a few moments and says: "I suppose most real writers are exiled in their minds always – whether from family, parish or country – because writing by its very nature is an extremely isolating and reflective job. Even though you are embroiled in the human stories, the work is done alone and in the crucible of the imagination."

This is O'Brien's first translation of a Greek drama but the novelist has long been a devotee of the Greeks – "It's the genesis of all drama. It's at one moment epic, but domestic" – and when rereading Euripides a few years ago found she was particularly drawn to this play. She decided to write a version because, she says, "Medea and Electra are often performed and this isn't. Iphigenia was the little foundling, if you like." Through a mutual friend she was introduced to the Crucible's artistic director, Michael Grandage, who commissioned it when it was already half written.

O'Brien has pretty much done away with the Chorus, changed Clytemnestra's and Agamemnon's stories, and added a pivotal character, as well as changing the ending. I suggest that she might have taken liberties, but O'Brien defends the reworking as necessary to allow a modern audience to see the significance of the play's action. "All the Greek dramas happen as a result of Iphigenia. This action here causes that effect there which catapults the action elsewhere into another war.

"This is a revisioning, if you like. Euripides left the play unfinished and the one that exists is supposedly taken from fragments he left, but I feel the very point, and terror, of the play is: will the girl be sacrificed for the men to go to war, or will she be saved? To muff that is a complete abnegation of what has gone before."

I remark that I am struck by how female-centred O'Brien's adaptation reads. "When you see it you might think differently," she says. "Agamemnon is at the centre of things and I think if Lloyd Owen [who plays the warrior] was sitting here he wouldn't agree with you.

"I would say rather than being female-centred it's a more equal representation of the power and presence of both male and female characters." Was that consciously done? "I don't work like that. If you think of what you are about to write, or is this politically correct or incorrect, you are limiting yourself. It just felt emotionally essential to write it this way."

Her staging is non-time-specific, and O'Brien hasn't given her adaptation any unnecessary modernities – "Putting somebody in a miniskirt is actually an irritation," she says. The play's language is direct, with flashes of poetical discourse but without any contemporary jargon. "It would be an insult," she says. "What I wanted to do was tell a story clearly while lessening the ornateness of the language. I revere Euripides and I made these changes not to diminish his play, but to allow the audience to identify with the story more thoroughly."

O'Brien has been a keen audience for others' interpretations of the Greeks, including a production of Oresteia by her old friend Sir Peter Hall. But she does not follow his route. "I know he very much values masques. I feel the very opposite. I think the masques mask both the features of the actors and the emotional pulse of the text. Peter would probably say it allows the actors to be freer. But I think it stultifies the part."

When O'Brien started writing Iphigenia, the Middle East crisis was at its height and now war with Iraq seems imminent. With lines such as "In time of war, unspeakable, unthinkable things are done" and "The anger of heaven is nothing to the anger of men", the parallels between ancient Greece and the modern world are inescapable. "The language and stance of George Bush's administration has been pugilistic from the start," agrees O'Brien. "They see themselves as the conquerors and the keepers of the universe. But that can only ignite matters."

But again, she did not consciously skew her adaptation, she says. "Unless we live in ivory towers we know that the world is more perilous than it has ever been. But I never thought I was going to write Iphigenia because the world is on the brink of war. It just happens that now, as it's about to be performed, it seems like a parable."

'Iphigenia': Crucible Theatre, Sheffield (0114 249 6000) to 1 March