The couple hit the green carpet on Sunday for the inaugural Earthshot Prize awards, an environmental initiative launched by Prince William. In keeping with the earth-friendly theme, guests were asked not to purchase new frocks or suits for the evening.
Kate, 39, 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; Julian Parker/UK Press via Getty Images Kate Middleton
Samir Hussein/WireImage; Dominic Lipinski - Pool/Getty Images Prince William
Kate's outfit choice may have also hinted at the location for next year's Earthshot Prize ceremony, which William announced will be in the United States.
Prince William, 39, 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.
Joe Maher/Getty Prince William and Kate Middleton
Presenter Emma Thompson said she came in the outfit she wore when she last saw Prince William — her 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.
Meanwhile, Emma Watson opted for an upcycled look created using secondhand bridal dresses by London-based designer Harris Reed.
Kate is known for her royal rewears, but her lilac gown marks the second time in a week that she's worn a piece that's been in her closet for years. Kate and William joined school children at a London park on Wednesday for a Generation Earthshot event to discuss ideas to help repair the planet, where she sported a green jacket also worn during the couple's 2014 tour of New Zealand.
Bev Hayes, a well-wisher who met Kate during the Cambridge, New Zealand visit seven years ago, previously said, "I complimented her on her green dress. She said she liked it but Prince William thought it was a bit bright."