Prince William and Kate Middleton lose family pet Lupo, who helped name Prince George

Prince William and Kate Middleton are mourning the loss of their beloved dog, Lupo, who passed away earlier this month.

The Duke and the Duchess of Cambridge took to their Kensington Palace Instagram account on Sunday, November 22, to share the heartbreaking news that they have lost their family pet at the age of 9. Alongside a gorgeous shot of the black beauty against the backdrop of snow, the couple wrote: "Very sadly last weekend our dear dog, Lupo, passed away. He has been at the heart of our family for the past nine years and we will miss him so much." They signed off the message with W & C, short for William and Catherine.

Lupo, an English Cocker Spaniel, joined the Cambridges soon after their royal wedding in 2011. A wedding present from Kate's brother James Middleton, the dog played a huge role in the lives of the royal couple as well as their three children, Prince George, Princess Charlotte, and Prince Louis.

The canine even helped select the name of the couple's eldest child, Prince George. William and Kate had organised a game where they wrote dozens of names on scraps of paper which they scattered across the floor of their home, and picked the one Lupo put its paws on.

Lupo, whose name is the Italian word for wolf, also appeared with the couple in their first family photo after George was born. He accompanied the family on their numerous trips and vacations over the last nine years.

Lupo was bred from Ella, a dog owned by the Duchess's parents- Michael and Carole Middleton. James Middleton took to his Instagram account to pay tribute to the pooch, writing: "It is with great sadness that Lupo, the beloved dog of my sister Catherine and her family has passed away."

"Nothing can ever prepare you for the loss of a dog. For those who have never had a dog, it might be hard to understand the loss. However for those who have loved a dog know the truth: a dog is not just a pet; it is a member of the family, a best friend, a loyal companion, a teacher and a therapist," the entrepreneur added.

To mourn Lupo's death, James said a prayer, lit a candle, and took the dog's mother Ella "for a long walk to spend time remembering Lupo."