Clementine is an intelligent, resourceful woman who grows up in genteel poverty due to her mother's bohemian lifestyle. Seeking stability, she marries up-and-coming politician Winston Churchill but refuses to serve as a silent, traditional wife. She tutors in French and takes in needlework to supplement her income early on, demonstrating a highly practical nature. She possesses strong political views, notably supporting women's suffrage, and actively works to secure an equal partnership in her marriage.

Winston is an aristocratic politician with an impeccable pedigree but limited financial means, forcing him to write and give speeches to supplement his income. Raised by a neglectful mother and a father who bullied him, he seeks attention and relies heavily on Clementine for practical political advice. He frequently changes political parties and holds various government offices, often prioritizing his ambition over his family's comfort.

Jennie is Winston's American-born mother, an heiress who prioritized her own pleasure and travels over raising her children. She begins to show interest in Winston only as his political prospects rise. Accustomed to getting her way, she attempts to exert control over her son's household, creating immediate friction with Clementine.

Lady Blanche Hozier is Clementine's mother, an aristocrat whose scandalous reputation and chronic financial mismanagement plunge her family into genteel poverty. She ignores the social strictures of her class, preferring to pursue her own affairs while leaving her children to the care of servants.

Nellie is Clementine's younger sister and Bill's twin. Grounded and deeply caring, she serves as a moral center for Clementine, offering honest feedback about her sister's demanding marriage. She shares Clementine's memories of their difficult childhood and acts as a constant source of emotional support.

Violet is the daughter of Prime Minister Herbert Henry Asquith. Entitled and lacking boundaries, she aggressively pursues Winston despite his relationship with Clementine. She functions as a rival who tests the boundaries of the Churchills' marriage, using her political connections and dramatic stunts to vie for Winston's attention.

Bill is Nellie's twin brother and Clementine's sibling. He shares in the siblings' difficult upbringing under their mother's chaotic household. He struggles with gambling debts and serves as a reminder to Clementine of the fragility of their family's standing.

Kitty is Clementine's eldest sister. She passes away at the age of sixteen, leaving a lasting impact on her surviving siblings and reinforcing the precarious nature of their early lives.

Diana is Clementine and Winston's firstborn daughter. Her birth initiates Clementine's complicated relationship with the domestic duties expected of aristocratic women.

Randolph is Clementine and Winston's second child and only son. Spoiled by his father, he grows into a temperamental individual whose outbursts frequently test Clementine's patience and energy.

Sarah is the third child of Clementine and Winston. She grows up in a politically charged household, eventually drawing the romantic attention of American diplomats who visit the family.

Marigold is Clementine's fourth child. She arrives during a period of intense political climbing for the Churchills, representing the domestic life Clementine struggles to balance with her political duties.

Mary is the youngest child of the Churchills. Her upbringing is largely handled by Clementine's cousin Moppet, allowing Clementine to focus more heavily on Winston's career.

As the Prime Minister of the United Kingdom, Asquith holds immense political power over Winston's early career. He maintains a complex relationship with the Churchills, balancing his political needs with the personal drama caused by his daughter Violet.

Venetia is Clementine's cousin and a close friend of Violet Asquith. She grew up in better economic circumstances than Clementine and occasionally criticizes Clementine's active involvement in politics, viewing it as unseemly for a woman of their class.

Lady St. Helier is Clementine's wealthy patroness. She provides the social connections and financial backing that allow Clementine to move within aristocratic circles, ultimately introducing Clementine to Winston Churchill at one of her formal dinners.

Terence is a fellow guest on a long yacht voyage that Clementine takes. He provides Clementine with companionship, admiration, and a fresh perspective on her marriage, gifting her a dove to symbolize her independence and personal transformation.

Eleanor is the First Lady of the United States. She forms a powerful bond with Clementine, as both women share the challenges of being married to demanding, historically significant men while attempting to carve out their own political identities.

Jock is Winston's private secretary. Initially skeptical of Clementine's active role in government affairs, he represents the traditional male establishment that Clementine must overcome to advocate for women's involvement in the war effort.

Moppet is Clementine's first cousin. She is hired by Clementine to serve as a caretaker for young Mary, providing domestic support as Clementine focuses on political matters.

Chamberlain is the Prime Minister who precedes Winston Churchill during the outbreak of World War II. His inability to halt German aggression paves the way for Winston's ascent to leadership.

De Gaulle is a French military leader who coordinates with the Churchills after escaping to England. He occasionally oversteps social boundaries, provoking Clementine's protective temper regarding British sacrifices.

Jack is Winston's brother. He and his family share a residence with the Churchills when financial and political struggles force them to economize outside of London.