The couple, both 39, stepped out on the green carpet Sunday for the inaugural Earthshot Prize Awards, an environmental initiative launched by William. During the ceremony, a previously recorded clip showed Prince William inside the London Eye, where he watched highlights from around the world since the start of the new millennium.
When footage of his own wedding to Kate from 2011 flashed on the screen, Prince William made eye contact with the camera. He gave a cheeky grin and raised his eyebrows before turning his attention back to the television.
Following the highlight clips, Prince William shared his concern about climate change, pointing out that scientists have declared the planet is at a "tipping point."
The royal also took the stage with a message of optimism for "all the young people watching tonight."
discovery/ Facebook Prince William
"For too long, we haven't done enough to protect the planet for your future. The Earthshot is for you. In the next ten years we are going to act, we are going to find the solutions to repair our planet," he said. "Please keep learning, keep demanding change, and don't give up hope. We will rise to these challenges."
Chris Jackson/Getty Prince William and Kate Middleton on their wedding day in 2011
In keeping with the earth-friendly theme, guests were asked not to purchase new frocks or suits for the evening.
In another tie to their wedding, Kate chose a lilac gown by her wedding dress designer Alexander McQueen. She previously wore the ensemble more than 10 years ago, when the couple attended a BAFTA event in Los Angeles during their 2011 visit to the U.S. However, she gave the dress a slight update, replacing the original belt with a bead-studded accessory from Jenny Packham's 2018 bridal collection.
Samir Hussein/WireImage Prince William and Kate Middleton
Prince William also pulled a previously worn piece out of his closet — an appropriately green velvet suit that he previously debuted in 2019 while attending the Centrepoint homelessness charity's 50th anniversary gala. Instead of the white shirt and bow tie he wore two years ago, William paired the suit with a black turtleneck for Sunday's Earthshot event.