Kate Middleton showers love on Prince William in loved-up photo from Earthshot Awards

Kate Middleton could not be more proud of her husband, Prince William.

Sunday night marked the inauguration of the much-awaited Earthshot Prize awards. Prince William and Kate attended the green carpet in black and white contrast outfits.

On Wednesday, the royal couple's office gave fans a glimpse of rare monochrome photos from the night.

In one of them, Kate and William were spotted walking hand-in-hand as they smiled ear to ear. In another, Kate was seen supportively put her arm around husband's lower back.

"The Duchess obviously felt really proud of what [Prince William] had achieved with this project. Seeing firsthand this realization of this huge amount of work for him. It was a really special evening," said source.