Princess Eugenie has paid tribute to her "special friend" Michelle Trachtenberg

Posting a photo of the pair on a night out, Eugenie wrote on her Instagram Story: "Goodbye, special friend. You are so loved and missed. Thank you for so many memories of laughter and fun. You were so thoughtful and generous and soooo funny.

"My favourite was listening to you order food, always done with precision so you got exactly what we all wanted. I'm thinking of you up there friend, of your spirit that was so bright and your joy you brought so many. [heart emojis] (sic)"

Michelle was best known for playing Dawn Summers, the sister of Sarah Michelle Gellar's titular character in 'Buffy the Vampire Slayer', and her co-star recently paid tribute to her.

Sarah's Instagram post was inspired by the show's season five finale, 'The Gift', in which Buffy sacrificed herself to save Dawn.

She wrote: "Michelle, listen to me. Listen. I love you. I will always love you. The hardest thing in this world, is to live in it. I will be brave. I will live... for you."

Alyson Hannigan, who played Willow Rosenberg on the teen drama, was "deeply saddened" by her former co-star's death.

She wrote on Instagram: "I am deeply saddened by the news of Michelle's passing.

"She brought a loving energy to the set of Buffy. My thoughts are with Michelle's family and friends."

David Boreanaz, who played vampire Angel, wrote on his Instagram Story: "So very sad ...horrible news. RIP and prayers to her and her family."

Emma Caulfield, who played former demon Anya Jenkins on the show, said the "Buffy family just lost a little sister".

She added: "I'm so sorry your bright light died so young.

"Our Buffy family just lost a little sister today... Rest in peace lovely Mish Mish. You were loved."

Kristine Sutherland, who starred on the show as Buffy and Dawn's mother Joyce, said in a statement: "I am devastated by the news of Michelle's death.

"The day she joined the Buffy family she brought a joy and innocence with her along with her talent.

"She was lovely to work with and will be missed. My heart goes out to her family."

Clare Kramer, who played villain Glory on the show, wrote: "Peace out little one. A talented + kind soul gone way too soon! You're free to fly now..."