The story unfolds on the eve of the 1997 British general election, marking a significant moment as Tony Blair, portrayed by Sheen, becomes the first Labour Party Prime Minister in the UK after an 18-year hiatus. During a session for an official portrait, the Queen (Helen Mirren) expresses her feelings to the artist, revealing her disappointment in not having the right to vote. Although she holds a slight apprehension towards Blair's commitment to "modernize" the country, Blair assures her of his respect for the monarchy's autonomy. Following tradition when Blair visits Buckingham Palace to kiss hands, the Queen formally asks him to form a Government in her name.
The plot thickens three months later when tragedy strikes during a visit to Paris. Diana, Princess of Wales, is killed in a car accident in the Pont de l'Alma tunnel, alongside her companion Dodi Fayed and driver Henri Paul. The fallout from this event is immediate; Blair's Director of Communications, Alastair Campbell, swiftly drafts a speech that famously labels Diana as "the people's princess." This phrase resonates deeply, igniting a surge of mourning across London, leading countless citizens to gather at Buckingham and Kensington palaces, leaving heartfelt tributes.
Meanwhile, at the Royal Family's summer residence in Balmoral Castle, located in Aberdeenshire, Scotland, Diana's passing creates a rift among senior royals. The Queen reflects on the circumstances: she is saddened yet maintains that since Diana’s recent divorce from Prince Charles (Alex Jennings), she is no longer a member of their family. This prompts the Queen to propose that the funeral remains a private occasion, meant for Diana's own family, the Spencers. However, a conflicted Prince Charles expresses his grief, emphasizing Diana's role as the mother of the future king, thus dismissing the Queen's approach. Eventually, following discussions, the Queen agrees to utilize the Royal Flight for transporting Diana's body back to Britain, and Charles ensures that her coffin is draped with a Royal Standard instead of looking like a mere "wooden crate."
As the sea of floral tributes at the palace grows, the tabloid media begins to critique the Royal Family for their silence. Charles communicates with Blair, underscoring a shared belief that a more visible expression of grief is essential. Amidst these tensions, the Queen's public approval ratings plummet, while Blair experiences a surge in popularity, much to the delight of his anti-monarchist advisors and his wife Cherie (played by Helen McCrory).
Despite the political advantage, Blair grapples with conflicting emotions. He respects the Queen and deems a Republican Britain as foolish. In a show of frustration, he rebukes his Labour advisors for their anti-royal sentiments, blaming Diana for undermining the monarchy's standing. Eventually, he reaches out to the Queen with urgent recommendations aimed at restoring faith in the monarchy, which includes attending Diana's funeral at Westminster Abbey, flying the Union flag at half-mast over Buckingham Palace, and delivering a live televised address honoring Diana's legacy.
These suggestions provoke outrage among the Queen's family, particularly with Prince Philip (James Cromwell) and the Queen Mother, who see such measures as capitulating to media frenzy. The Queen, while echoing their sentiments, begins to reconsider her position, affected by the shifting public sentiment. A conversation with her mother reveals her internal conflict, where the Queen realizes that she may need to adapt to changing values in society. The Queen Mother, however, reassures her of her vital role, famously stating, "The real problem will come when you leave."
Amidst the emotional turmoil, Philip tries to divert his grandsons from their mother's death through deer stalking. Meanwhile, during a solitary drive, the Queen faces a mishap with her Land Rover, leading her to a moment of vulnerability as she waits for assistance. During this time, she observes the majestic Red Deer stag, symbolizing her royal connection to nature, yet grapples with the sad reality of life and death.
In a climactic turn of events, the Royal Family returns to London, reflecting on the countless floral tributes lined up in front of the palace. The Queen delivers a poignant televised speech honoring Diana, acknowledging her as "an exceptional and gifted human being." Two months down the line, Blair visits Buckingham Palace again for their routine meeting. While the Queen has restored her image among the public, she laments the lasting impacts of "that week." She offers a cautionary note to Blair about the volatility of public opinion and acknowledges the necessity for the monarchy to evolve. When Blair proposes assistance with this transition, the Queen sternly reminds him, "Don't get ahead of yourself Prime Minister. Remember, I'm supposed to be the one advising you."
