Princess Eugenie is mourning the loss of her “special friend,” actor Michelle Trachtenberg. The royal posted a moving tribute to the late actor on her Instagram Story this week. Trachtenberg, 39, was confirmed dead on Wednesday after her mother discovered her in her New York City apartment.

Eugenie became friends with Trachtenberg when she lived in New York City and worked for the art auction start-up Paddle8 from 2013 to 2015. Their friendship first became public in December 2013, when they were photographed courtside at a Knicks game alongside actor Michael K.

The NYPD confirmed Trachtenberg was found “unconscious and unresponsive” by police and pronounced dead by EMS workers. Her death is not deemed suspicious. Trachtenberg shared a throwback photo with Instagram followers on Feb. 18. The close-up shot showed the “Gossip Girl” vet on the red carpet.