Princess Victoria of Kent is the heir presumptive to the British throne during the reign of her uncle King William IV and is subject to a political tug of war for influence over her. On one side is her mother, the Duchess of Kent, and the comptroller of the Duchess's household, Sir John Conroy, who tries to force Victoria to sign papers declaring a regency and giving him and her mother power. On the other side is her uncle, King Leopold I of Belgium, who wishes to use his influence through family ties to secure an alliance between the United Kingdom and Belgium. He decides to have his nephew Prince Albert of Saxe-Coburg-Gotha charm and marry Victoria, and he has Albert be coached in her likes and dislikes. The Duchess invites the Coburg brothers, Albert and Prince Ernest of Saxe-Coburg-Gotha, to visit the household. Victoria and Albert develop an early fondness for each other, despite Victoria knowing that their uncle sent Albert to win her favours. They begin writing to one another after Albert returns home.
At a birthday reception in Windsor Castle, the King states his wish to be closer to Victoria and insults her mother. But when the King increases Victoria's income, this is rejected by Conroy, who physically subdues her in front of her mother, heightening the animosity between them. The King then sends the Prime Minister Lord Melbourne to advise her. Victoria agrees to make him her private secretary, and he appoints ladies-in-waiting for her from political families allied to him.
King William dies after Victoria's 18th birthday, avoiding a regency. After accession, Victoria immediately begins to exert her independence, including moving into her own room and banishing Conroy from her household and coronation. During her first meeting with the Privy Council, she announces that "I mean to devote my life in service of my country and my people". Victoria now moves into the recently completed Buckingham Palace and her aunt, Queen Adelaide, advises her against giving in too much to Lord Melbourne's direction. Albert then comes to England to spend more time with Victoria. They bond more, dancing together at her coronation ball and later discussing together the condition of the poor. Albert hints at taking their relationship further, but the self-sufficient Victoria resists, and he leaves.
When Lord Melbourne loses a vote in Parliament, the new Prime Minister designate, Sir Robert Peel, wishes to replace some of her ladies-in-waiting with supporters of his own party, and the queen refuses. In turn, Peel refuses the queen's invitation to form a new government, allowing Melbourne to continue as Prime Minister. The subsequent crisis damages Victoria's popularity, leading to demonstrations outside the palace and insults hurled at her in public. Her loneliness during the turbulence draws Victoria closer to Albert through their letters, and she decides to invite him back to Britain. Since protocol prevents him from suggesting marriage, she proposes to him herself.
Their honeymoon is short but loving, yet soon Albert is frustrated at his initial powerlessness, and Queen Adelaide advises Victoria to allow him to take on more duties. He then reorganises the running of the royal household and dismisses Conroy for mishandling funds. As Victoria's primary adviser, he now blocks the influences of Lord Melbourne and King Leopold. However, Victoria quarrels with him fiercely for going over her head with Peel in her household.
When an ararchist tries to shoot Victoria as they are riding in an open carriage, Albert throws himself across her in front of the bullet and is wounded. This bravery leads to their reconciliation, and Melbourne advises her to share with Albert her work for social welfare too. Their first child's birth helps heal the breach between Victoria and her mother, who had earlier sent a letter of support during the crisis.
The final title card sketches in their successful future until Albert's death at 42.
Emily Blunt as Queen Victoria
Rupert Friend as Prince Albert of Saxe-Coburg and Gotha
Miranda Richardson as the Duchess of Kent
Mark Strong as Sir John Conroy
Jim Broadbent as King William IV
Harriet Walter as Queen Adelaide
Paul Bettany as Lord Melbourne
Thomas Kretschmann as King Leopold I of Belgium
Jesper Christensen as Baron Stockmar
Jeanette Hain as Baroness Louise Lehzen
Julian Glover as the Duke of Wellington
Michael Maloney as Sir Robert Peel
Michiel Huisman as Prince Ernest of Saxe-Coburg and Gotha
Rachael Stirling as the Duchess of Sutherland
Genevieve O'Reilly as Lady Flora Hastings
David Robb as Lord John Russell
based on the early life and reign of Queen Victoria, and her marriage to Prince Albert of Saxe-Coburg and Gotha.