In 1521 England, Queen Catherine of Aragon's failure to provide King Henry VIII a male heir has strained their marriage. Thomas Boleyn and his brother-in-law Thomas Howard, the Duke of Norfolk, plan to install Boleyn's youngest daughter Mary, wife of courtier William Carey, as the king's mistress. Mary's sister Anne, who recently returned from the French court, and brother George help Mary prepare, and Henry soon takes a liking to Mary. Meanwhile, Queen Catherine becomes displeased with the situation, as she considered Mary one of her dear ladies-in-waiting. Before long, Mary becomes pregnant with the king's child.
Both the Howard and Boleyn families receive lands and titles as a reward for their service, elevating their status amongst the other noble families of the royal court. Anne catches the eye of Henry Percy, heir presumptive to the Duchy of Northumberland, and marries him in secret. Percy, however, is set to marry Mary Talbot, the daughter of the Earl of Shrewsbury. Cardinal Thomas Wolsey discovers and forbids the union. Anne's family sends her to Hever Castle as punishment for the potential scandal.
Mary gives birth to a daughter in 1524 and names her Catherine. While disappointed, the king becomes determined to impregnate her with a son, and Mary soon becomes pregnant again. George marries Jane Parker, another of the queen's ladies-in-waiting, but their marriage is unhappy. Anne returns to court on her family's orders to ensure Henry is not distracted from Mary. Instead of doing as she's told, Anne seduces the king and wins him over. Mary eventually gives birth to a son, who she names after the king. She realizes, however, it is not enough as everyone will consider the child illegitimate.
As Mary focuses her attention on her children and starts losing favor with Henry, her family begins supporting Anne in her quest to win the king over. Anne puts pressure on Henry to set Queen Catherine aside, refusing to give in to his desires until they are married. Henry, however, finds himself unable to do so with religious opposition. With Anne entertaining the king, Mary is tasked with sleeping with him to prevent his attention from going elsewhere. She visits her children every summer at Hever and soon reconciles with her husband.
Eventually, Queen Catherine stands trial for the validity of her marriage to Henry. The king believes she consummated her previous marriage with his dead brother, Prince Arthur, and did not come into their marriage a virgin. The Queen is banished, and Anne, now engaged to marry Henry, adopts Mary's son to ensure she has a male heir to the throne. Mary, meanwhile, loses her husband to the sweating sickness. Anne's determination to become queen reaches new heights while George becomes the subject of suspicions that he is engaging in relationships with male courtiers.
Essex landowner William Stafford begins courting Mary, who becomes attracted to him because of his love for her children and the possibility of living the simple country life he can offer her. Anne suffers a decline in popularity during her travels abroad, culminating in the King and Queen of France, who do not tolerate her position, refusing to meet her. She eventually sleeps with Henry after he grants her a title and marries him when he installs a new archbishop and proclaims himself Head of the Church of England. Anne gives birth to a daughter in 1533, who she names Elizabeth. Mary marries William but receives orders to stay at court until Anne gives birth to a son. Anne, however, starts to lose the king's favor after several miscarriages and stillbirths.
Henry suffers an injury to his leg while jousting in 1536, and his time recovering stokes worries that public sentiment is turning. Meanwhile, Anne grows increasingly paranoid, convinced she has lost the support of her family and the country and that Henry is in love with lady-in-waiting Jane Seymour. She rejoices in her new pregnancy after hearing news of Queen Catherine's death but soon miscarries. Henry discovers the child was born severely malformed and begins courting Jane Seymour as rumors that Anne is a witch spread.
Mary makes plans with William to travel for the country to avoid the turmoil. Before they can do so, Henry places Anne and George under arrest on charges of adultery and incest due to widespread belief that they slept together to give Anne her much-needed son. Anne later presents herself before the Privy Council, which finds her guilty. George and his lover are also convicted and beheaded.
Anne is sent to the scaffold on the promise that her punishment is exile to a nunnery. As it becomes clear that King Henry will not be attending, Mary realizes that he intended to execute Anne, who dies by beheading. Mary leaves London with William and both children the same day.
