Designers don't usually star in each other's campaigns, but Riccardo Tisci has made an exception for one very special woman: Donatella Versace. He's tapped the Versace designer for the new Givenchy AW15 campaign, photographed by Mert & Marcus and styled by Carine Roitfeld.

Donatella and Tisci are both pictured side by side in the black-and-white image, looking sombre but united. The Givenchy designer posted the first campaign image on Instagram, writing: "So proud and honored to introduce my new ultimate icon : Donatella Versace....FW 15 Givenchy Family Campaign MORE TO COME SOON".

Donatella paid the favour back by tweeting the image from Versace's account with the words: "For my talented friend Riccardo. Together we break fashion boundaries today!"

Givenchy has a strong history of delightfully unexpected casting; past campaign stars have included Julia Roberts and Erykah Badu. But casting a fellow designer in a campaign? That's definitely a new one. What do you think of this surprise pairing?