The Luxembourgish royal wore a sky blue gown very similar to the teal Jenny Packham dress that the Duchess of Cambridge sported at an Olympics gala ball in 2012.
The stunning gown, which featured an intricate lace bodice and sheer back, was a princess-perfect choice for a late summer wedding.
Kate's was a bespoke version of the vintage-style 'Aspen' dress and very similar to the one sported by Princess Alexandra at the wedding of her brother Prince Felix to Claire Lademacher.
While fashionista Kate wore her dress with metallic Jimmy Choos for her soiree, Alexandra opted for shoes more appropriate for the daytime nuptials – nude patent heels – which are incidentally one of Prince William's wife's trademark looks.
It wasn't just Princess Alexandra that had succumb to the 'Kate effect'. Witnesses at the wedding who included Lola Toscani and Maria Sanchez also wore the floor-length number.
Princess Alexandra wasn't the only member of the Grand Ducal family who had looked to her royal contemporaries for fashion inspiration.
The beautiful bride Princess Claire of Luxembourg wore a dress very similar to the one chosen by Princess Stephanie of Luxembourg for her wedding to Prince Guillaume last October.
PhD student Claire's floral detail long-sleeved gown echoed the Elie Saab gown wore by her now sister-in-law Stephanie for her Luxembourg ceremony last year.