Finally, a film that gets Diana right

Last night saw the premiere at the London Film Festival of Spencer, easily the most credible biopic of Diana, Princess of Wales, yet to make it to the screen.

It’s not the script that makes it so good, however. It’s the sumptuous photography by Claire Mathon; the bracing, antsy music by Jonny Greenwood, Pablo Larraín’s hypnotic direction; and a fabulous Kristen Stewart, in a role very likely to provide her first Oscar nomination.

This worked out dandily for Natalie Portman when she starred for Larraín in Jackie, and it’ll work for Stewart too. She inhabits the part with close to eerie verve, and brings a stamp to Diana that’s definitively her own: an air of high-strung exasperation, a fretful kind of intimacy. We feel drawn inside her secrets and her pain.

It’s the kind of performance Naomi Watts surely wishes she’d given a decade ago, rather than the career-worst one she contributed to the jawdropping Diana (2013) – a film so tonally deranged and dramatically abominable it’s scarcely a surprise that Spencer improves on it vastly.

Before that, the only notable attempts to get Diana’s life on screen were a series of infamously tacky TV movies, two of which starred Catherine Oxenberg, a real-life member of the Serbian royal family: The Royal Romance of Charles and Diana (1982) and Charles and Diana: Unhappily Ever After (1992).

These boasted useless production values and C-list casts, with the exception of the award-winning actress Holland Taylor as Diana’s mother and Olivia de Havilland as the Queen Mum. A Princess in Love (1996), inspired by James Hewitt’s memoir, cashed in with Barbara Cartland-ish glee on Diana’s extramarital adventures, and Diana: A Tribute to the People’s Princess (1998), even more gallingly, on her death.

As all of these prove, it’s been hard to dramatise Diana’s life without an element of camp intruding: it’s just a matter of staying in control of it, which Spencer does rather masterfully. Diana managed to emanate it completely by mistake, in every look and exchange between Watts’s princess and Naveen Andrews’s heart doctor Hasnat Khan, especially on the much-derided date scene when they go to a branch of Chicken Cottage.

That all-time howler of a script was convinced of the clever metaphor it had found whenever the pair set to discussing Hasnat’s profession. It had Diana ordering in a copy of Gray’s Anatomy, which instantly fell open on an illustration of the old ticker. “So hearts can’t actually be broken?” she kept asking Hasnat, with head-on full tilt.

There’s another insane scene where Watts puts on a squawking Scouse accent as a disguise. Later, she explains (and this is actual dialogue): “Yes, I’ve been a mad bitch, yes, I’ve been a stalker, yes, I put on a crummy Liverpudlian accent to get your attention, but I was trying to provoke you.” On all fronts, it’s the kind of film that makes criticism fairly easy.

Larraín is far too smart a filmmaker to make mistakes on that scale, even if the match-up between this Chilean art-house darling and Spencer’s screenwriter, Peaky Blinders’ Steven Knight, is a pretty bizarre one, giving some of the drama an awkward, Google Translate flavour. Laden with a surprising amount of dialogue, Spencer could have done with much less – the film is consistently quite blunt with its themes, and Diana’s chronic obsession in it with the fate of Anne Boleyn verges on overkill.

It’s the inverted fairytale of the unhappy princess, her mystique, and her outsider status that have evidently captured Larraín’s imagination more than anything else. These are all reasons why Stewart, with her air of misfit angst and queer/emo fan following, is such an interesting choice for the part. Larraín has said Stewart’s “mystery and magnetism” made her his favourite for the role, meaning he had to help the film’s financiers overcome their qualms about hiring an American. Counter-intuitive though it might seem, Stewart’s casting is Spencer’s major triumph. As an actress, she could hardly feel less establishment, less like a royal. There’s something fraught and rebellious in her very being.

Over the film’s three-day span – the final Christmas before Charles and Diana’s separation – Diana is screamingly discontented and has had enough: of the scrutiny, the rigid wardrobe protocols, the obsession over what she’s eating. The film comes on very strong as commentary on her bulimia – even more than her feelings about motherhood, this is secretly its main subject.

Stewart plays that material for all its worth – capturing this woman’s indignant fight for bodily autonomy, but also the despair and self-disgust behind a series of closed bathroom doors. The film keeps us staunchly on her side, and ruffles up her status as a fashion icon into the bargain: as she swishes down Sandringham’s corridors in an array of Christmas frocks, expertly curated by Jacqueline Durran, she seems in charge of the clothes and also bored of them.

There’s a rebel-chic quality to this portrait which Stewart sharply understands and milks deliciously, with that edge of camp that knows what it’s doing. The film is not perfect, but the irreverence and cheek of it, and the empathetic focus on this alienated heroine of her own life story, make it the only essential Diana film there is.

Spencer is released on November 5