Crown Princess Mary wears one of Kate Middleton's go-to designers, while more European royals stun at Opera House banquet

It was a night at the opera for Queen Sonja and King Harald of Norway’s royal birthday party guests. A number of Europe’s most stylish ladies stepped out on Wednesday for a banquet held at Oslo’s Opera House, which was the third royal-studded event of the monarchs’s joint multi-day celebration to mark their 80th birthdays.

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VER GALERÍA Crown Princess Mary with husband Crown Prince Frederik (left) and Crown Princess Victoria and Prince Daniel (right) Photos: NESVOLD, JON OLAV/AFP/Getty Images/Patrick van Katwijk

Crown Princess Mary of Denmark took a page out of Kate Middleton’s book donning a design by one of the Duchess of Cambridge’s favorite designers, Erdem. The Danish royal stunned wearing a long-sleeve, full-length gown that featured a "Yuki Garden" print by the London-based designer. Mary wasn’t the only future Queen making a floral statement at the May 10 event. Crown Princess Victoria of Sweden wore a sleeveless black gown by Acne Studios that featured bold flower prints and a modest side slit.

VER GALERÍA Crown Prince Pavlos and Crown Princess Marie Chantal Greece (left) and Princess Tatiana and Prince Nikolaos of Greece (right) Photos: Patrick van Katwijk/Getty Images

Crown Princess Marie-Chantal of Greece made a colorful splash arriving to the gala wearing a pink tiered gown by Valentino. The Greek royal’s sister-in-law, Princess Tatiana, also stunned for the occasion wearing an ethereal white Celia Kritharioti Haute Couture dress. Like Tatiana, Princess Sofia of Sweden also wore white for the evening. Prince Carl Philip’s wife, who is expecting her second child, dressed her growing baby bump in a tiered crochet dress by Alexis clothing.

VER GALERÍA Princess Sofia, Queen Maxima, Queen Mathilde and Crown Princess Mette-Marit Photos: Patrick van Katwijk/Getty Images

Meanwhile, Queen Maxima of The Netherlands, Queen Mathilde of Belgium and Crown Princess Mette-Marit of Norway opted for navy shade gowns. Maxima looked regal recycling a gold off-the-shoulder dress by Claes Iversen — which she previously wore in 2016 — that featured a midnight blue lace overlay at the neckline with similar lace designs on the skirt. While Mathilde and Mette-Marit twinned in navy gowns with sequin embroidery.

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