Princess Beatrice's husband, Edoardo Mapelli Mozzi, was among those to pay a heartfelt tribute to the Princess of Wales in honour of her 43rd birthday on Thursday.
In a message that almost went under the radar, Edoardo took to Instagram to respond to Prince William's personal written message which was released alongside an unseen photograph of Kate.
© Matt PorteousIn the comments section, Edoardo simply added a heart emoji while the Princess' brother James Middleton also left a heart and cake emoji.
The celebration comes shortly after Edoardo, 41, and his wife Beatrice, 36, joined Prince William and Kate in Sandringham for Christmas.
In a touching and rare move for Kate's birthday this year, Prince William made a public declaration of his and their children's love for the royal, telling her, "We love you," after a turbulent past year which saw her diagnosed with cancer.
© GettyIt was accompanied by a new black and white picture of Kate taken by Matt Porteous, in Windsor, last summer, showing the Princess looking relaxed and smiling with her hands in her jean pockets and wearing a gingham scarf.
In response, doting brother James added a birthday and heart emojis underneath the comments section of the post.
"To the most incredible wife and mother," Prince William wrote in his message. "The strength you've shown over the last year has been remarkable. George, Charlotte, Louis and I are so proud of you. Happy Birthday, Catherine. We love you. W."
Kate celebrated her day quietly at home in Windsor with William, with Prince George, Princess Charlotte and Prince Louis spending the day at school before a family celebration in the evening.
The Princess has endured a challenging past 12 months which saw her undergo abdominal surgery, be diagnosed with cancer and face chemotherapy treatment.
