The duke and duchess of Cambridge attended the awards show Sunday at Royal Albert Hall in London.
Guests were invited to "dress sustainably," which Middleton followed by re-wearing a dress she previously sported at a 2012 state dinner in Malaysia. The white Alexander McQueen gown features gold trim and floral embroidery.
William, who is president of the British Academy of Film and Television Arts (BAFTA), gave a speech during the ceremony. He addressed the lack of diversity among the BAFTA nominees, which were all white actors in the top four categories.
"Both here in the U.K. and in many other countries across the world, we are lucky to have incredible filmmakers, actors, producers, directors, and technicians: Men and women from all backgrounds and ethnicities, enriching our lives through film," William said. "Yet, in 2020 and not for the first time in the last few years, we find ourselves talking again about the need to do more to ensure diversity in the sector and in the awards process. That simply cannot be right in this day and age."
American actor Joaquin Phoenix, who won Best Actor in a Leading Role for his portrayal of the title character in Joker, went farther in his acceptance speech, calling on the industry to dismantle a "system of oppression."
William and Middleton laughed off jokes during Brad Pitt's acceptance speech for Best Actor in a Supporting Role for Once Upon a Time in Hollywood. Pitt's co-star Margot Robbie read Pitt's speech for him in his absence.
"He starts by saying, 'Hey, Britain. Heard you just became single. Welcome to the club!'" Robbie said, reading Pitt's joke about Brexit. "'Wishing you the best with the divorce settlement.'"
"Oh, and he says that he is going to name this 'Harry,' because he's really excited about bringing it back to the [United] States with him," Robbie said.
William's grandmother, Queen Elizabeth II, gave the prince a new title and role last week following Harry and Markle's decision. William is second in line to the throne, after his father, Prince Charles, and has three children, George, Charlotte and Louis, with Middleton.