Cowes Week, 1873; Jennie Jerome, a beautiful spirited young American, meets Lord Randolph Churchill aboard the flagship HMS Ariadne. There is an immediate and powerful attraction, and three days later Randolph proposes. Jennie accepts - but neither expect the total opposition they face to their engagement.

Jennie finds the Marlborough family overbearing and Blenheim Palace stuffy, but she knows as soon as her confinement is over she will resume her social life in London. A son, Winston, is born. Jennie's return to the London social scene is cut short by scandal...

Randolph's political career recovers after a stint in Ireland but having grown apart from her husband, Jennie embarks upon an extramarital affair with a dashing Austro-Hungarian nobleman, Count Karel Kinsky.

Five years after the death of her first husband, Lord Randolph Churchill, Jennie gets re-married to George Cornwallis-West who is the same age as her oldest son Winston.

Jennie's marriage to second husband George Cornwallis-West crumbles when famed actress Mrs. Patrick Campbell casts her roving eye upon George and they begin an extramarital affair.

In 1918, at the age of 64, Jennie gets married for a third time to civil servant Montague Porch, who is three years younger than son Winston.