Moreau, the first French actress to appear on the cover of Time magazine, started in classical theatre just after the second world war, then went into films and spearheaded the nouvelle vague. She has worked with legendary actors and directors. In 1998 she won an Oscar for lifetime achievement. In 2001 she was inducted into the Académie des Beaux-Arts – the first woman in its nearly 200-year history. This made official her status as an immortelle. In short, Moreau is the greatest actress in France, perhaps anywhere. And her speciality is the strong woman, the seductress, the uncontainable animal spirit.

Having done my research, I’m not surprised to find that she is short. I know, too, that she has contempt for cosmetic surgery, and indeed any attempt to prevent the effects of ageing. That being said, she’s still, at 78, one of the most glamorous people I’ve ever met. Her hair is bobbed and she wears a smart black jacket over jeans. On her left hand she wears a ring with a gigantic pearl.

She places on the table before her a box of cigarettes; she manages not to smoke while we talk, but her voice is huskier than any you’re likely to hear outside a cancer ward. She sits on a sofa. I take a chair. But she says she can’t hear me properly and invites me to sit beside her. Over the course of our conversation, perhaps by way of punctuation, she touches me several times on the hand. Also on the elbow. Possibly the thigh too, but the interview passes in such a blaze that I’m afraid I can’t quite remember.

According to my notes, we start by discussing Jules et Jim. “Still today, on the streets of New York,” she says, “people stop me and say, ‘What a marvellous story.’ And I say, ‘Do you remember the end?’ And they don’t.” The end is tragic. “Catherine can’t have her dream of loving both men, so she takes the car and drowns herself and her lover.”

So how does Moreau account for the film’s energetic, exuberant mood? “We started Jules et Jim with very little money. There was a very small crew – we only had a sound man on the day we recorded the song, and everything else was post-synched – so there was a great sense of freedom. It was very inventive. François [Truffaut] would say, ‘I’m going to rewrite that scene.’ He was reinventing all the time.

“Making a film is like a voyage,” she explains. “You have to take your luggage, as Orson [Welles] used to say. You discover a little world, you discover other people, and you discover humanity. You get deeper and deeper into the human mind. It’s an incredible adventure.”

Jules et Jim was released more than 40 years ago. Moreau is famously indifferent to nostalgia, and I am conscious that to talk about such an ancient work must be frustrating. So we move on. She has come to the Istanbul Film Festival to collect another lifetime achievement award; afterwards, there’s to be a showing of her latest film – Time to Leave [Le Temps Qui Reste], where a young man finds out he has only months to live. The only person he confides in is his grandmother, played by Moreau. It’s a small part, but she makes the character incredibly real.

“My face has changed with the years,” she explains. “It has enough history in it to give audiences something to work with.” Rather cruelly, the grandson tells Moreau’s character he’s confiding in her because, like him, she’s going to die soon. How does Moreau, approaching 80, feel about death?

“I saw my first body when I was seven. I was surrounded by religious people who talked about paradise and all that shit. In the war, I saw violent death. In Paris, at the end, I saw an old German soldier: his clothes were torn apart and people were beating him to death. That was horrible, but we should not be against death. We all face it. Death is a mystery. But it’s what makes life interesting and suspenseful.”

She had a strong taste of mortality in 2003. For many years, Moreau has delighted in living on her own, at a rented apartment in Paris. (“I need absolutely to be alone,” she once said.) But in September that year she was woken in the night by an intruder. Moreau – who, like her character in Time to Leave, sleeps in the nude – handed over jewellery and valuables worth nearly £300,000. Today, understandably, she doesn’t discuss her living arrangements.

Moreau’s mother, Kathleen Buckley, was a Tiller Girl from Oldham who went to Paris in the 1920s to dance at the Folies Bergère with Josephine Baker. She fell in love with a Frenchman, Anatole Moreau. “I believe they got married only because she got pregnant,” says their daughter, “although nobody ever talked about that.”

Anatole’s family never accepted Kathleen. “She danced on stage with her breasts showing. Can you imagine! My grandmother was very religious, but she asked my mother why she didn’t have an abortion. Even abortion would have been better than for her son to marry my mother.” (Moreau’s own attitude to abortion is straightforward. In 1971 she risked prosecution as one of 343 well-known Frenchwomen to publicly acknowledge having had an abortion.)

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