King Lear is a play of extremes and absolutes, says Kathryn Hunter, and therefore appeals to adolescents. She has been obsessed with it since school days, never imagining she would play the title part.

But Ms Hunter has often worked with director Helena Kaut-Howson, whose own family circumstances led her to the idea of a female Lear. A brief prologue to the production at Leicester’s Haymarket Theatre shows a family visiting their aged mother in an old people’s home. The mother feels rejected by the family that put her there. In turn she spurns them.

“Lear is a despot who has lived to a ripe old age,” says Ms Hunter. “He doesn’t know how to give love, although he needs it himself in great measure. So he becomes more and more isolated. The play sees his spiritual awakening and a less self-obsessed vision - he never notices the ‘naked wretches’ until he becomes destitute himself.”

Ms Hunter has been reminded of a 20th-century despot. Lear shares with Stalin the paranoia that accompanies megalomania. Paranoia might seem a strange accusation - Lear’s two daughters are actually out to get him. But Ms Hunter sees it lying behind the opening, “in the monstrous demand he makes at the start. The loss of Cordelia to a husband is important. When she says she will not marry ‘to love my father all’, it is the last strand in his isolation. ”

So Lear throws out anyone, like Kent, who questions his authority (at least Kent was spared a show trial). And the treatment he receives from Goneril and Regan shows. “His children are his children. He’s begot that way of thinking in them. They feel no parental connection and lack the values of respect, loyalty and integrity that do not demand something in return,” says Ms Hunter.

Elements of the hospital prologue recur in Pawel Dobrzycki’s designs - Lear’s throne sits atop a hospital trolley for a start. And in a stylistic device familiar from Theatre de Complicite (with which Hunter and Marcello Magni, who plays the Fool, are closely linked), members of the 14-strong cast also function as a chorus - Lear’s knights, his daughters’ servants and common people suffering in the raging civil war. This chorus gives “a sense of the world. The wars we do not see, the world breaking apart, ordinary people being affected”, says Ms Hunter, “giving greater impact to announcements that Lear’s side is winning or losing in battle”.

There is significance in this wider view. What happens to the nation reflects Lear’s belief that he can confer fertility (the luscious lands he gives away) or sterility (which he wishes on his ungrateful offspring). Ms Hunter says: “Shakespeare set the play in primitive times to remove the Christian securities of justice and redemption, because then, as today, we mostly have no faith in them. Hence it’s his darkest play.” Lear says “As flies to wanton boys are we to the gods.” Hunter is convinced that only the fear of censorship kept Shakespeare from substituting “God” for inoffensive pagan deities. “When humans start cutting off connections with each other and choose self-gratification, there are no limits to cruelty. If we don’t have values, we open the way to chaos,” she says.

There remain practical decisions for the actor. Ms Hunter is a woman playing a man: this is not Queen Lear. And she has to consider what happens in the old man’s mind when Lear is offstage. Ms Hunter has no doubt what is preoccupying him. In guilt or regret, he can hardly bear to mention by name the daughter he rejected, or face her again, but the name that will be filling the Haymarket’s wings during Lear’s absences is Cordelia.

King Lear, Leicester Haymarket until March 15. Tickets: 0116 253 9797.