'Spencer': How does Kristen Stewart's Princess Diana movie stack up?

Watch: Trailer for Kristen Stewart as Princess Diana in Spencer

Eyebrows were raised in some quarters when Spencer was announced. Kristen Stewart, it's fair to say, is not the most obvious choice to take on the role of the People's Princess. Not only is she American, but the meme-powered hangover provided by the Twilight saga means that, to a lot of viewers, she's seen as a bland actor capable of few facial expressions.

For the record, that was never true. Stewart has always been a great actress with real range but, that couldn't be clearer today after her work in the likes of Personal Shopper, Seberg and — showing her comedic chops — Happiest Season and Charlie's Angels. Not only does she do consistently great work, but she does it in a huge variety of films.

Read more: Kristen Stewart says she feels protective of Diana

Still, Stewart is a divisive figure and seemed an unconventional choice for the darling of the British public — and the British tabloids. In the film. Stewart's take on Diana says with frustration that "I'm a magnet for madness — other people's madness" and that's as true today as it was when she was alive.

Diana still looms large over British popular culture, which is presumably what attracted Chilean filmmaker Pablo Larraín to this movie, scripted by Peaky Blinders creator Steven Knight.

Larraín has form with biopics of this kind, having helmed the 2016 Jackie Kennedy film Jackie, which earned Natalie Portman an Oscar nomination for her portrayal of arguably the most famous First Lady in US history. That movie was a strange, impressionistic portrait of a woman in the midst of intense pressure, attention and emotional turmoil.

Read more: Natalie Portman plays iconic First Lady in Jackie

Spencer does something similar, unfolding over three days during the Christmas of 1991. Diana is at Sandringham, celebrating the festive season with her husband (The Riot Club's Jack Farthing) — despite their obvious marital problems — and the entire royal family. Newspaper photographers are reportedly circling, desperate for a scoop on the royal scandal, and the beady eyes of Timothy Spall's watchful equerry are fully fixed on Diana.

It's a more conventional and accessible movie than Jackie, but still one which embraces Larraín's dreamlike eye for the biopic, assisted by Radiohead guitarist Jonny Greenwood. It's part costume drama, part psychological thriller and part gothic horror. Seriously.

How good is Kristen Stewart in Spencer?

K-Stew is currently the frontrunner for the Best Actress Oscar for her work in Spencer, with most UK bookies currently giving you something in the region of 6/4 odds for her victory. Watching the movie, it's easy to see why she's in pole position. It's a fabulous performance.

Early photographs and trailers were enough to showcase Stewart's uncanny transformation into the princess and the very solid, clipped English accent she is deploying in the role. Stewart has said she immersed herself in recordings of Diana and would fall asleep listening to her voice — and that research has certainly paid off.

Read more: Stewart says she was "hounded" as a queer actor in Hollywood

In the opening scenes of the film, Stewart's Diana is driving aimlessly in the vicinity of Sandringham and running late for the beginning of the festivities, pulling into a roadside café to ask for directions. It's the first time we see Diana in her full glory and, certainly, Stewart dials up the affectation — giving the voice both barrels and coquettishly tilting her head. What's most impressive, though, is that this single moment is the only time her work feels cartoonish. From that point onward, she disappears completely into the role.

Larraín's direction and Knight's script give Stewart plenty of opportunity to broaden Diana beyond simply being the icon we already know, giving her a sarcastic acidity in the face of po-faced royal traditions, as well as the turmoil of a woman in the midst of a mental health struggle. If the Oscar does come her way, it'll be richly deserved.

Is Spencer historically accurate?

One of the smartest moves Spencer makes is to set its action very specifically across three days in December 1991. It's not a cradle-to-grave biopic exploring every facet of Princess Diana's life, nor is it a chronicle of the collapse of her marriage. The movie captures her in a snapshot of her life, dealing with suffocating royal traditions and trying to be a mother to her children while gently pushing back against the restrictions of being part of the Windsor clan.

In terms of the accuracy of Christmas at Sandringham, Stewart has said there was an advisor on set to ensure the characters were "remaining authentic" in their depiction of royal milieu. This includes the bizarre practice of everyone — yes, even the Queen herself — being weighed on arrival at Sandringham and when they leave, in order to ensure they've been well-fed over Christmas — a tradition dating back more than 100 years to King Edward VII.

Read more: Michael J. Fox sat next to Diana at Back to the Future premiere

Larraín, in an interview with IndieWire, made the film's intentions clear in terms of depicting the reality of Diana's life. He said: "We aren’t trying to explain who she was or answer questions on the larger scale of her life. We’re fictionalising most of it based on what we think could have happened.”

The movie doesn't shy away from depicting Diana's struggles with bulimia, which were also recently handled by The Crown with Emma Corrin's Golden Globe winning take on the princess.

Diana revealed in her famous 1995 interview with Martin Bashir that she struggled with the eating disorder for several years during the breakdown of her marriage. In Spencer, we see Diana frequently being sick after meals — the subject of a cruel jibe by her husband — and sneaking into the kitchens late at night to eat.

Read more: Is season four of The Crown its best run yet?

Another very real tradition depicted in Spencer is the royal family's Boxing Day pheasant shoot. In the film, Diana is adamant that William and Harry should not partake in the shoot, whereas their father is equally sure they should wield the firearms. There is some debate about whether this distaste for blood sports rings true with reality. Diana famously referred to her sons jokingly as "Killer Wales" for their proficiency with rifles and she herself reportedly shot a stag at Balmoral — as also shown in The Crown's fourth season.

Diana's protection officer Ken Wharfe, however, wrote in 2014 that the princess believed the royal obsession with shooting was "repugnant". Royal expert Katie Nicholl echoed this in her book Kate: The Future Queen, contrasting Diana's reluctance to take part in the tradition with Kate Middleton's enthusiastic participation in the sport.

Does Spencer criticise the royal family?

It's fair to say that the royal family probably won't be putting Pablo Larraín on their Christmas card lists.

Spencer strongly focuses on the ways in which Princess Diana felt suffocated by the outdated customs and attitudes of the royal family. She arrives late for numerous occasions during the film and rebels by wearing her pre-arranged outfits in the wrong order. It's a minuscule act to just about all of us but, within this tightly-wound bubble, it's as punk rock as you can be.

Prince Charles, in particular, does not come off well. He's portrayed in sinister fashion, making unpleasant comments about his wife's eating disorder and lecturing her about the need to play by the rules, while malevolently moving snooker balls around. Jack Farthing's performance is slimy and loathsome, which will likely upset the same royal experts who criticised Josh O'Connor's take in The Crown.

Read more: Josh O'Connor feels defensive over Prince Charles

Ultimately, it's compelling to watch Spencer in the context of the current royal turmoil around Meghan Markle and Prince Harry's decision to leave frontline duties. Many of the points Markle raised in her interview with Oprah Winfrey will ring true to anyone watching the brilliant Spencer, which depicts Diana as an innocent woman at the centre of a right royal nightmare. Those gothic horror elements are no accident.

Spencer is screening at the BFI London Film Festival and is due to be released in UK cinemas on 5 November.

Watch: Kristen Stewart expecting criticism of Spencer accent