It is one of the most eagerly-anticipated movies of the year and delves into Princess Diana's decision to end her marriage to Prince Charles.
And last night the film, called Spencer, got its UK premiere with Twilight actress Kristin Stewart taking on the coveted role of Diana.
Set in 1991, the film documents the late princess spending three days with the royal family at Sandringham, where she decides to finally end her turbulent marriage to the future King.
The film's title takes its name from Diana's family name of Spencer. Before she was married, she was known as Lady Diana Spencer.
But who is part of the Spencer family now, and what do they do? Here we reveal all...
The model newlywed
Among the most well-known of the current crop of Spencers is Diana's niece and Princes William and Harry's younger cousin, Lady Kitty Spencer.
The 30-year-old hit the headlines in July when she married wealthy businessman Michael Lewis, 62, in a stunning three-day wedding in Italy.
She wore a series of gowns by Dolce & Gabbana with her main dress, which had an intricate floral lace design, a high neck, long sleeves and puffed shoulders, reportedly taking six months to create.
The couple exchanged their vows in front of celebrity guests that included singer Pixie Lott, and Idris Elba's wife Sabrina at the Villa Aldobrandini in Rome.
Kitty is Earl Spencer's oldest child and grew up in South Africa with her mother Victoria.
She read psychology at the University of Cape Town and has modelled for brands including Dolce & Gabbana and Bvlgari.
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She also scored invites to the wedding of her cousins William and Harry and her Instagram account shows her at fashion shows in cities such as London and Milan.
Although the monarchy has now changed to put sons and daughters on an equal footing in terms of ascending to the throne, British primogeniture law has not been changed to peers such as dukes and earls.
So her father Earl Spencer's title will go to his eldest son Louis rather than Lady Kitty.
Glamorous twins
Sometimes joining their sister Kitty at events and parties are twins Lady Eliza and Lady Amelia Spencer.
They were born in 1992 and grew up in South Africa and were just five when their late aunt Diana died.
Earlier this year, they gave a rare joint interview in Tatler where they shared fond memories of their "incredibly warm, maternal and loving" aunt.
Speaking about Diana's death in 1997, Eliza said: "As a child, I realised the enormity of the loss for my father and family.
"It was only later that I came to understand the significance of the loss of her as a figure in the world.
"We always just knew her as our aunt. Growing up in South Africa, I really had very little idea of how significant she was in the world until I was much older."
Curiously, Amelia didn't attend cousin Harry wedding to Meghan in 2018, but Eliza was there.
Both twins are models and are represented by Storm Management.
Prince Harry-lite
Another member of the Spencer family is Kitty, Amelia and Eliza's younger brother Louis, who has been dubbed 'the world's most eligible bachelor' as well as 'Prince Harry lite'.
He is a fair few years younger than his royal cousins William and Harry but in the past, it has been reported that he is close to them.
Louis, 27, is said to be 'super private' but earlier this year, he played a starring role in sister Kitty's wedding, as he walked her down the aisle.
One day he will inherit the family's 13,500-acre Althorp estate in Northamptonshire as his father, Earl Spencer's heir apparent - despite having three older sisters.
Kitty previously said: "We've grown up understanding that it's Louis to inherit, and Louis will do an incredible job."
Head of the family
The current head of the Spencer family and holding the title of Earl Spencer is Diana's younger brother Charles.
He is the custodian of the family's Althorp estate in Northamptonshire and has been married three times.
As well as having children Kitty, Eliza, Amelia and Louis, he also has younger children Edmund, Lara and Charlotte.
Charles counts the Queen as one of his godparents and was extremely close to Diana - delivering a moving eulogy at her funeral in Westminster Abbey in 1997.
However, when his eldest daughter Kitty wed this summer, there was reportedly no sign of her father at the nuptials.
An insider claimed the Earl may have skipped his daughter's big day due to a shoulder-related injury.
A source told MailOnline at the time: "Charles recently suffered an injury and perhaps that will be the reason for him not travelling, but it is just easier for everyone that he is not there."
Prince Charles's ex
Lady Sarah McCorquodale is Diana's eldest sister and even briefly dated Prince Charles as a teenager.
She married Neil McCorquodale in 1980 and they have three children - Emily, George and Celia.
Diana was said to be close to Sarah and she sometimes accompanied her on engagements as a lady-in-waiting.
After Diana's death, she accompanied Prince Charles alongside her other sister Jane to bring the princess back to the UK.
In 2019, she attended the christening of Harry's son Archie's christening and was at the unveiling of a statue of Diana in July.
Royal wedding star
Lady Jane Fellowes is another of Diana's older sisters and is married to Robert Fellowes - a former private secretary to the Queen.
She has three children - Laura, Alexander and Eleanor - and gave readings at the funeral of her sister as well as at nephew Prince Harry's wedding in 2018.
She too was at Archie's christening and the unveiling of the Diana statue.
