Princess Beatrice's quirky headgear was the talk of the royal nuptials, with critics divided on the daring sculptural design.
Now, Philip Treacy – the hatmaker to the stars, who created a staggering 35 headpieces for guests at the Abbey – has entered the discussion, calling his creation "absolutely amazing".
At the gala in London's Mandarin Oriental Hotel, Beatrice sparkled in a white and silver sheath dress by Australian designer Rachel Gilbert.
The lovely pale hue set off her auburn tresses to perfection. Adorned with sequins and featuring a tulle fishtail train, the gown made her look like a mermaid, suddenly washed up in SW1.
Meanwhile, younger sister Eugenie was sultry in a black, asymmetrical Vivienne Westwood number, with shoulder embellishment adding some sparkle to the corseted dress.