Lifestyle Style Kate Middleton's Royal Blue Issa Dress for a Royal Engagement By People Staff Published on November 17, 2010 03:00 PM Share Tweet Pin Email Samir Hussein/WireImage What does one wear to announce her own royal wedding to Prince William in front of cameras around the world? While it would send most of us mere mortals into a wardrobe meltdown, Kate Middleton simply called upon her favorite brand Issa. The London-based fashion label has become the Brit’s go-to designer of choice over the years, thanks to her love of their elegant wrap dresses and glamorous evening gowns. Opting for one of their classic silk jersey dresses in navy (all the better to sparkle against that dazzling blue sapphire engagement ring) and simple black pumps–her look was princess perfect. As pictures of the happy couple at St. James Palace were beamed across the globe on Tuesday evening, Issa designer and Middleton friend Daniella Helayel told PEOPLE she couldn’t be happier that one of her dresses had been chosen for such a momentous occasion. “We are thrilled with the engagement news and I’m very happy that she has chosen to wear Issa today,” adding, “She is a very pretty and lovely girl.” Fueling speculation that the bride-to-be will wear Issa on her wedding day, Middleton recently wore a bespoke dress that Brazilian-born Helayel whipped up especially for her (based on a dress Middleton already had in her closet). But as dress predictions mount, we’ll simply have to wait and see. One thing we can be sure of is that a style icon is emerging and this one is here to stay. —Monique Jessen PHOTOS: SEE KATE MIDDLETON’S 10 STYLE ESSENTIALS!