Kate Middleton and Prince William met with Norway's Prince and Princess at Windsor Castle.

The royals posed for a new portrait together, which the Prince and Princess of Wales shared on Instagram.

Princess Catherine looked stunning in a brilliant turquoise pantsuit, while Prince William looked handsome in a navy blue suit with a ruby red necktie.

Princess Mette-Marit wore a bright red gown, while Prince Haakon wore a light blue suit with a blue-and-white polka dot tie.

The meeting's purpose was to discuss common environmental concerns.

They all sat down with three leading Norwegian companies to brainstorm potential environmental projects.

Prince William is deeply committed to environmental issues, as evidenced by his establishment of the Earthshot Prize.

The Earthshot Prize aims to recognise and fund individuals who are working to save the planet.

The gathering gathered a lot of royal star power in one picture.