Catherine Brandon, née Willoughby is the fourth and final wife of Charles Brandon and therefore the Duchess of Suffolk. She is the only female character apart from Princess Mary Tudor to appear in all four seasons. She is played by Irish actress Rebekah Wainright in a recurring role. Her relationship with her considerably-older husband is initially very loving and produces a number of children, but becomes badly strained in Season Three and they ultimately never reconcile before his death.
Catherine is briefly seen in the Season One finale at the Duke of Suffolk's estate when Charles introduces her to his friend, Sir Anthony Knivert. Charles explains that the 17-year-old is his ward before privately telling Anthony that they have plans to marry (despite the fact that Charles' previous wife, Princess Margaret, has only just died in the previous episode). Anthony remarks on her beauty, which Charles agrees with.
King Henry asks Charles about his hew marriage, teasing his friend about his lack of fidelity and the youth of his bride; however, Charles seems happy in his married life, telling Henry "It's a marriage of true souls." Privately, he truly hopes to remain a faithful husband, and tells Catherine "... to you, I will always be true", though he cautions her that he may cause her pain due to his amorous nature. Catherine seems equally happy with her marriage, settling into a role of stepmother to Edward, Charles' young son by Margaret.
While Catherine's religious views are left ambiguous as the Reformation begins in England, she clearly has great sympathy for the banished Queen Catherine of Aragon and so, like Charles, has a thorough dislike of the new Queen Anne Boleyn and her family. While Charles angrily rants to his wife whenever Anne's behavior offends him, Catherine prudently tells him not to act impulsively, but to store up his anger; one day, he may have an opportunity to attack Anne when she is vulnerable.
Unfortunately for Catherine, Charles' previous warnings about his fidelity comes true when she learns that Charles cheated on her (2.06). Nonetheless, Catherine reconciles with him when Charles, feeling guilty, begs her forgiveness. By the end of the episode, she and Charles are expecting a child.
During Season Three, Catherine appears to have overcome his infidelity and are once again happy with their marriage. However, this is soon uprooted by Charles' role in suppressing the "Pilgrimage of Grace" in the North; he is appointed commander of the Royal Army and sent to crush the rebellion. Concerned for his safety, Catherine bids him farewell and gives him advice: despite being a pro-Reformer, she urges Charles to take a merciful approach towards the pro-Catholic rebels, as opposed to Henry's commands for bloody repression. Initially, Charles is able to negotiate an end to hostilities without any violence. However, when a second, minor uprising occurs, he violently and angrily crushes it on Henry's orders.
To Catherine's horror Charles is ordered by Henry (who was potentially prodded into doing so by Thomas Cromwell, though this seems unlikely) to go back to the North and make a "fearful example" by executing thousands of civilians (3.03). Catherine pleads for him not to do such a thing even if it means facing the King's wrath, comparing the innocent civilians to their own children. Charles grimly says that even then he would still have to obey Henry's commands. Horrified and disgusted, Catherine leaves the room.
When Charles leaves to go North, he pleads to Catherine not to hate him for his actions, and she asks him again (more calmly) to show mercy to the Northerners; he does not, and their deaths continue to weigh on his conscience. Charles joins Catherine in prayer and feebly argues (more to himself than to her) that he has done right by his conscience in obeying his King and carrying out the massacre (3.04). When he is done speaking, Catherine flatly tells him that she is pregnant, then walks away. When he later shows concern for her health, she admits she fears the child will be haunted by the ghosts of the children Charles was forced to execute; therefore, she wishes she were not bringing the child into the world.
When Charles later meets with King Henry (who is mourning the death of his third wife, Jane Seymour), Charles tells Henry that Catherine had a miscarriage (3.05). Catherine and Charles remain uncomfortable and cold towards each other, unable to reconcile.
Through the remainder of Season Four, Catherine is phased out as a character, though Charles mentions her on occasion. They live separately and, although Charles at first refuses to take a mistress, saying to Henry "I'd rather make her love me again, if I could.", he eventually concedes.
Catherine is mentioned late in Season Four by Edward Seymour; apparently she and Seymour's wife, Anna Stanhope, are friends and co-supporters of the Reformation. Near the end of the series finale, Catherine is briefly seen at her husbands' funeral, along with her son; she acts cold and aloof towards Charles' mistress Brigitte.
Catherine Brooke is based on Catherine Willoughby (22 March 1519 – 19 September 1580), the fourth wife of Charles Brandon, 1st Duke of Suffolk, who acted as her legal guardian during his third marriage to Mary Tudor, the younger sister of Henry VIII. An outspoken supporter of the English Reformation, she fled abroad to Wesel and later Polish–Lithuanian Commonwealth during the reign of Queen Mary I, to avoid persecution. Unlike the television portrayal, the marriage was a successful one despite the large age gap (Suffolk was forty-nine and Catherine only fourteen when they married). She was a close friend of Catherine Parr, and they once angered Bishop Gardiner, by dressing a puppy as a bishop and calling it Gardiner.
- She is half Spanish, her mother Maria de Salinas, was one of Catherine of Aragon's Spanish handmaidens.
- It's mentioned by Richard Riche, that she is one of Catherine Parr's attendants.