The world was reminded over the weekend that the British royal family does not have a monopoly on beautiful photocalls. The reminder came courtesy of Princess Katharina-Amalia of the Netherlands, who turned 21 on Saturday (December 7) and seemed to celebrate the occasion by taking the idea of “casual chic” style to a whole new level.

In two new photos shared by the Dutch royal family on Instagram, Catherine-Amalia looked perfectly put together and completely comfortable in a black sweater, wide-leg blue jeans, and an open gray overcoat.

“De Prinses van Oranje viert vandaag haar 21ste verjaardag,” the Dutch royal family wrote in the simple caption of the Instagram post (which translates to “Princess Orange celebrates her 21st birthday today”).

The carousel post included two previously unpublished photos of the Dutch princess, a classic close-up and a stunning wide shot of the princess looking almost wistfully into the distance.

The new photos, which debuted on the Dutch royal family's Instagram account in honor of Katharina-Amaria's birthday, were evidently taken as part of a group photo shoot the family held in November.

According to royal commentator Amanda Matta, Katharina-Amalia was joined by her father, King Willem-Alexander, her mother, Queen Maxima, and her two sisters, Princesses Alexia and Ariane, for the photo shoot on November 29 at Begginhof in Amsterdam, Amsterdam to celebrate the city's 750th anniversary.

As for how else Princess Orange (a title given only to the heir to the Dutch throne) is celebrating her milestone birthday, Point de Vue reported in November that a grand ball is being prepared. Meanwhile, Hello! Magazine reported that while the Dutch royal family has not officially confirmed the reported plans for the celebration, “If a celebration dinner is held, the invited guests are likely to include other European heirs, and the dress code will be white tie.”

Given her self-proclaimed love of tiaras, Cattarina-Amalia would gladly approve of the ultra-formal dress code.

“I love tiaras,” she said in Claudia de Bry's book Amalia. 'If you show me a tiara, I know where it came from. I know tiaras from all over Europe. I got my tiara from my mother. The tiara was on my mother's dressing table, and I put it directly on my head."[17