Sir William Compton was one of King Henry's original circle of close friends. He was played by the Canadian actor Kris Holden-Ried.
Like Charles Brandon and Anthony Knivert, William is low-born, and is therefore mistrusted, slighted, and resented by noblemen such as the Duke of Buckingham and the Duke of Norfolk. However, he still accompanied Henry along with Charles and Anthony in most of his activities: tennis matches, jousting, hunting, and even to the Val D'Or for the peace summit in France.
William and Anthony later avenged themselves on Buckingham for his various snubs when they arrest him for treason on Henry's orders (Episode 1.02), which led to his execution.
Though he has a tendency to be arrogant, William has a charming personality and an excellent sense of humor, which is demonstrated in Episode 1.04: after losing a jousting match with Henry, he carried a tree-trunk under his arm across the field as if to joust, claiming that it is a "trick". Pleased with William's humor and good sportsmanship in losing, Henry later knighted him after bestowing a similar title on Anthony.
Later on, William was forced to act a mediator between Henry and Charles, the latter of whom had married the King's sister without permission. He seemed to be slightly surprised and off-put by the depth of Henry's relationship with Anne Boleyn, but knowing Henry's womanizing habits, he did not think much of it.
William genuinely enjoys the company of his friends, but does not join them in womanizing, pretending that he prefers drink to sexual activities - although he was shown to take a common-law wife: Anna Hastings, the daughter of the Duke of Buckingham. Though Anna seemed to regard him with affection, it gradually becomes evident that this marriage was more likely to be a cover, as William was revealed to be secretly homosexual.
As shown in Episodes 1.04 and 1.05, William fell in love with Thomas Tallis, the talented young bisexual composer and court choir director, and discreetly courted him. Though Thomas appeared to attempt to resist, he grew to reciprocate William's love, and they entered into a secret yet intense love affair. However, their relationship was tragically cut short: while Thomas was away in France, William contracted the sweating sickness and died despite the efforts of the royal physician, Dr. Linnerker. He was amongst the first of the many victims of this plague.
Thomas, Henry, Anthony, and Charles all mourned his passing respectively.
In the series, William was shown to be a tall, well-built, and soigne-looking man with blonde hair and blue eyes.
- William Compton: (watching King Francis and King Henry wrestle) "Two kings, two queens and a fool." Anthony Knivert: "Who's the fool?" William Compton: "I don't know yet, but it's a full house."