The royal pair stunned on the green carpet. Photo / Getty Images
Prince William and Kate Middleton have taken to the green carpet in stunning fashion, with William rocking green velvet and Kate re-wearing an iconic Alexander McQueen gown.
The pair joined a star-studded line-up of presenters and performers to announce the winners of William's inaugural Earthshot Prize.
Prince William used the event to set the course for what he feels will be a decade of change where the world comes together to combat the climate crisis.
Guests of honour William and Kate set the tone of the carpet, asking guests to not purchase new outfits for the evening.
Kate re-wore an Alexander McQueen gown she previously wore in LA on the last night of their 2011 tour. And William wore a very James Bond-inspired green velvet suit, complete with a turtleneck. A strikingly bold look for the Prince, that hit the mark and was perfect for the occasion.
Presenter Emma Thompson also followed the wardrobe rules, set by the couple, wearing the outfit she wore when she last saw Prince William — a stunning suit and the badge that signifies her damehood.
"On our little notes they said 'Please do not buy anything new for this.' Can you imagine? The relief! So I got my dame suit that I wore when I went to the palace," she shared.
She spoke about the evening as an opportunity to help counter big issues like food waste, saying, "One of the solutions is going to be here and that makes me happy".
The evening was a chance to celebrate the 15 finalists in the Earthshot awards, with five winners soon to be announced, one each from five categories that Earthshot organisers have deemed critical focus areas: Protect and Restore Nature, Clean Our Air, Revive Our Oceans, Build a Waste-Free World, and Fix Our Climate.
The five winners will each receive a nearly $2million prize to help with their work.
The Duke and Duchess of Cambridge will host a ceremony each year to award five more recipients the resources they need to pursue solutions for repairing the planet.
"This is an absolutely incredible community," finalist Sam Teicher, who is working to restore coral reefs, told PEOPLE before Sunday's event. "The other finalists are so inspiring. We're already thinking about the synergies that exist between us all and the different partners within the Earthshot community."
Teicher continued, "There are a lot of people talking about Earthshot and these solutions and the other solutions out there. ... [T]here's already good progress being made because of Prince William."
On Thursday, Prince William shared his hope that he wouldn't hand down the "burden" of worry about the planet to his children, 8-year-old Prince George, 6-year-old Princess Charlotte, and 3-year-old Prince Louis.