Nancy is the 28-year-old eldest Mitford sister. She is an aspiring novelist hoping to balance a literary career with a traditional family. A moderate within her family's extreme political factions, she observes her sisters' radical choices with mounting concern. She struggles with personal betrayals but maintains a sharp perspective on her changing world.

Diana is a 22-year-old society beauty. She maintains a wealthy aristocratic lifestyle with her husband and children but soon feels unfulfilled. Seeking greater purpose, she becomes captivated by fascist politics. She openly risks public scandal to pursue her ideological and romantic ambitions, displaying intense self-assurance.

Unity is the 18-year-old Mitford sister. Physically towering over her peers, she feels acutely uncomfortable in traditional high society. Searching for belonging, she finds absolute order in fascist ideology. She becomes intensely focused on Adolf Hitler, making plans to move to Germany and immerse herself in his inner circle.

Sir Oswald Mosley is the charismatic, married founder of the British Union of Fascists. A known womanizer with immense political ambition, he seeks to install an autocratic regime in Britain. He leverages his personal charm and social connections to secure funding and support for his political movement.

Adolf Hitler is the leader of the German Nazi Party. He commands absolute loyalty and leverages the admiration of foreign aristocrats to project international support for his regime. He is a volatile and controlling figure who uses his proximity to power to manipulate those eager to enter his inner circle.

Muv is the matriarch of the aristocratic Mitford family. Bound by traditional societal norms and focused on preserving her family's elite status, she often appears detached from her children's deeper emotional needs. She shifts her political allegiances based on what best preserves her personal comfort and social standing.

Farve is the patriarch of the Mitford family and a veteran of the First World War. He represents the declining traditional aristocratic lifestyle in an era of economic depression. Initially anti-German due to his military past, his political views fluctuate as his daughters become increasingly involved with radical movements.

Peter Rodd is a banker from an aristocratic family who becomes Nancy's husband. Despite his pedigree, he struggles with chronic unemployment and severe alcohol misuse. His unreliability puts a significant strain on his marriage, though Nancy remains determined to build a family with him.

Winston Churchill is a prominent British politician and a longstanding friend of the Mitford family. Astute and deeply concerned about the rising threat of fascism in Europe, he recognizes the danger of Hitler's regime early on. He acts as a political counterweight to the Mitford sisters' radicalization.

Decca is the 15-year-old Mitford sister who firmly embraces communism, putting her at ideological odds with her fascist-leaning siblings. Despite their bitter political arguments, she initially maintains a close bond with Unity. She is fiercely independent and willing to rebel against her aristocratic upbringing.

Bryan Guinness is a wealthy writer, aristocrat, and heir to a barony. He provides Diana with an extravagant society lifestyle, multiple properties, and a seemingly perfect family life, making her sudden desire to leave him a massive public scandal.

Hamish is Nancy's former fiance. He breaks off their longstanding engagement, causing Nancy deep emotional pain but freeing her to eventually meet and marry Peter Rodd.

Cimmie is Sir Oswald Mosley's wife. Despite her husband's blatant infidelity and involvement with Diana, Mosley refuses to leave her, creating a complex romantic rivalry.

Baba is Cimmie's sister and one of Sir Oswald Mosley's mistresses. Her relationship with Mosley creates intense jealousy in Diana, further complicating the tangled romantic and political web surrounding the fascist leader.

Putzi Hanfstaengl is Hitler's foreign press secretary. He acts as a guide and facilitator for the Mitford sisters during their early trips to Germany, using his association with Hitler to help integrate them into the fascist social circle.

Evelyn Waugh is a famous writer and artist in London. He is part of the elite, intellectual social circle that Nancy cherishes, representing the literary world she hopes to conquer.

Unterfeldwebel Schwarz is an SS officer and one of Hitler's bodyguards. He takes a romantic interest in Unity, flattered by her proximity to Hitler and eager to show her the rising power of the Nazi regime.

Pamela is the 25-year-old Mitford sister. Unlike her highly political and ambitious siblings, she prefers a quiet country life and avoids the turbulent extremes that divide the rest of the family.

Debo is the youngest sibling in the Mitford family. Only 12 years old at the start of the narrative, she observes the fracturing of her family from the periphery as her older sisters pull in radically different directions.

Tom is the 23-year-old and only brother of the Mitford family. Surrounded by headstrong sisters, he manages the complex social expectations placed upon the sole male heir of a declining aristocratic family.

Esmond Romilly is a staunch communist who shares Decca's radical left-wing politics. He represents a complete rejection of the Mitford family's aristocratic privileges and fascist leanings.

Jonathan Sims is a solicitor who administers the money Mosley receives from his late wife's family. He represents the legal and financial establishment that occasionally impedes the couple's ambitious plans.

Peter Eckersley is a British fascist sympathizer and radio engineer. He is a crucial technical contact for the covert political broadcasting plans that Diana attempts to orchestrate.

Jonathan is one of Diana and Bryan Guinness's young sons. His stable aristocratic childhood is upended when his mother decides to leave his father for a new political and romantic future.

Desmond is one of Diana and Bryan Guinness's young sons. His early life is marked by the immense privilege of his family, which is later disrupted by his mother's scandalous choices.