Princess Eugenie is mourning the death of Michelle Trachtenberg. The youngest child of Prince Andrew and Sarah Ferguson, the Duchess of York, the 34-year-old princess took to her Instagram Story on Thursday to pay tribute to the late “Gossip Girl” star,

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.