In 1988, a young Akram Khan stepped on to the stage in Glasgow's Tramway - part of the global company that had toured Peter Brook's Mahabharata to venues across the world.

The programme shows him in a thumbnail picture - a solemn 14-year old in a turban - alongside a biog that is surprisingly packed with incident for such a young performer. It notes that he'd been giving public performances since the age of five: London's Roundhouse and the Queen Elizabeth Hall were among the venues mentioned while - as well as dancing - he'd played the young Mowgli in a theatre production of The Jungle Book to "much critical acclaim".

The Akram Khan sitting opposite me in the cafe at Sadler's Wells is 40 this year. "Much critical acclaim" has followed him wherever he has danced, choreographed and collaborated since. As he pauses to find the right word to put motion (and emotion) into words, one thing is already apparent: this month, a chapter that began with Brook's Mahabharata is about to close. The forthcoming performances of Gnosis will, in effect, mean one part of his life and art has come full circle. It will, like that old 1988 programme, become the stuff of cherished recollections.

Loading article content

"We had actually closed the door on Gnosis already," he says, his voice and smile gently amused. "But when [Edinburgh International Festival director] Jonathan [Mills] asked us if we could bring it to the Festival... that made us think 'why not? We can take another look at it.' Tweak one or two things, maybe add something - and we have. We have brought in extra musicians, because - for this festival - it has to be special. So for Jonathan's last festival, we will give the last and final performances of Gnosis."

Cast an eye over the narrative substance that inspired Gnosis and you soon see how this piece fits into a festival programme where war looms large across the various art forms. Khan has based his choreography on characters and actions from the Mahabharata, the Hindu epic that has warring families wreaking havoc and destruction on each other, as well as on mankind itself. He's wonderfully frank about how, during his time under the directing influence of Peter Brook, he didn't spend every waking hour thinking "I am in the presence of genius". Instead, as a fidgety, restless teenager, he went looking for things to do. Scaling the red-brick back wall of the Tramway space was one gambit that Brook put a stop to, declaring they weren't insured for such antics.

But there was a part of that mercurial, energetic teenager that subconsciously absorbed everything that was going on around him, from the personal tragedies and cosmic catastrophes that weaved in and out of the epic nine-hour staging, to the values that Brook brought to his multicultural vision of storytelling. "Usually, in mythology, it's the male characters who are always celebrated," says Khan. "They are the centre of every story, women are seen as secondary. But Peter Brook recognised that in the Mahabharata there were female characters who were equally as powerful as the men. And that equality really interested me. And actually, without Gandhari - whose story I use in Gnosis - there would be no Mahabharata. No war. Because she has the ability to see the future, and she knows that her eldest son, Duryodhana, will be the catalyst for destruction... and yet she chooses not to kill him. She is a queen, a woman who has such power. But she is also a mother."

Khan himself is now a father, with a little daughter who is not yet two years old. Her presence in his life is, he says, a constant reminder of how - as adults - we take too much for granted, stop noticing how much beauty and wonder there is around us in the world. Gnosis, however, was already in process before her arrival. What was it, then, that attracted him to Gandhari, her choices and her tragedy?

"I think your own experience, your own relationship with your mother, makes you curious about this woman," Khan says. "What will a mother do for her child?" His own was, and continues to be, a major influence in his life. Her own ambitions to be a dancer were frowned upon by her family in Bangladesh, so maybe she saw in her hyperactive toddler son something of that yen: she enrolled him in dance classes when he was just four. His status as a creative powerhouse within both traditional Kathak and contemporary dance proves her instincts were right.

As for Gandhari, what of her instincts? Khan muses thoughtfully on what it must have meant to her - an intelligent, highly educated,highly cultured woman - to be forced into marriage with an old, blind king simply because it suited the political manoeuvrings of other men.

"She blindfolded herself. But whether that was so as her husband wouldn't feel inferior to a sighted queen, or whether it was a form of defiance - refusing to look at him, his court, the world she had been forced into - is a matter of opinion. And there are many opinions! But her inner eye could see that she would have 100 sons, but lose them all if she didn't forestall the war by killing her first-born. Her choice to keep him alive leaves her with an internal war that never leaves her. She lives in darkness, a powerful queen who is powerless to act against her maternal feelings."

On-stage in Gnosis, Khan is Duryodhana to the Gandhari of Fang-Yi Sheu, a Taiwanese dancer who was, for many years, the leading light of the Martha Graham Company in America. There were various fits and starts to the evolution of Gnosis, not least because injury intervened - Khan damaged his shoulder - and the London premiere was compromised as a result.

"I felt, really, that I had failed big time," he says. An unfamiliar experience for someone who was recruited to be part of the London 2012 opening ceremony and who has collaborated to memorable effect with a gamut of well-known artists ranging Antony Gormley to Kylie Minogue and Juliette Binoche.

Shoulder healed, he reflected on what Gnosis needed to fulfil his intentions of a narrative duet where his own Kathak technique and contemporary dance training could inform a modern choreography, one rooted in ancient mythology but with universal, timeless concerns. The music was already in place, likewise the shadows and glimmers of the lighting design - but where was Gandhari? "As soon as we saw her [Fang-Yi Sheu], we knew. And we stopped looking, because here was the dancer who already had both the physical depth, and the emotional depth of our Gandhari."

As he goes on to describe more of what he means, his hands are tending to sculpt the air, as if Gandhari/Fang-Yi Sheu will take on holographic form beside us. He talks not just of movement, but of stillness. "Gandhari doesn't speak out loud, but she is speaking through her silence. And her silence, her stillness, really command you. Pull you into her story. We needed a dancer who could understand that, inhabit it, perform it - believe in it and make you believe in it too. We found that very special dancer: Fang-Yi Sheu."

Gnosis is really only the half of what audiences will see on-stage in this programme. The first half is a showcase of Kathak solos where Khan lays down the traditional ground rules, as it were. That way, when any Kathak accents come into the modern movements in Gnosis, audiences will recognise where the rapid rhythmic footwork, spins and stylised hand and arm gestures come from. But even in the first half, where heritage is heard in the live music as well as in Khan's ankle bells, there are nods to a classicism that is Western: there is a cellist.

"Ahhh, the cello..." Khan waxes lyrical. "It can be masculine, it can be feminine. It can be monstrous, it can also be fragile. Violin for me doesn't have that - it has the sense of hecticness, but it can't resonate, like a deep sea monster, or fly sweetly like a bird." His enthusiasm has a boyish elan. So when our talk turns to matters of 'how much longer...?' and Khan murmurs "maybe five more years. But Kathak only: anything else gets too hard, too risky" then, indeed, the sense of chapters ending creeps in a little closer.

"Ends are also beginnings," he says as he heads off to rehearse a new duet with a flamenco dancer. Audiences worldwide will hang on to those words. Meanwhile audiences in Edinburgh have the final Gnosis in their sights.

Gnosis is at King's Theatre, Edinburgh from August 19-21,