Pregnant Kate Middleton Wears Princess Diana's Favorite Tiara During Annual Winter Party

Kate Middleton wore Princess Diana's favorite tiara on her recent sighting.

On Tuesday, Middleton and Prince William stepped out together to attend the annual winter party. The queen hosted the reception for diplomats at Buckingham Palace. It is one of the largest parties that the monarch hosts annually.

For the occasion, the Duchess of Cambridge wore the Queen Mary's Lover's Knot tiara. The headdress is Princess Diana's favorite, People reported. Middleton paired the diamond tiara with pearl drop earrings and a diamond necklace. Prince William seemed to be a fan of the same accessory because she also used it at the reception in the previous year.

According to the publication, the tiara is already over a century old and was originally commissioned by famous court jewelers Garrard in 1913 or 1914. It's a replica of the 200-year-old Gothic revival that Queen Mary's grandmother, Princess Augusta of Hesse, the Duchess of Cambridge. That is why it is also called Cambridge Lover's Knot.

The original tiara had been auctioned and was sold in Geneva in May 1981 for over $747,000. The buyer was unidentified. But many presumed that the headdress is in an unknown private collection.

The royal mom of two who is expecting her third child with Prince William has been using different accessories from the queen's vault. For instance, Middleton wore Queen Elizabeth's Quatrefoil diamond bracelet when she graced the Anna Freud National Centre for Children and Families (AFNCCF) gala in November. The monarch wore the same piece over her signature white gloves at the State Opening of Parliament in 2010.

In addition, the Duchess of Cambridge borrowed the queen's pearl-diamond choker when she attended her 70th wedding anniversary with Prince Philip. Princess Diana was also spotted wearing the four-strand pearl choker with a central diamond in 1982 for the state banquet in Netherlands.

When Meghan Markle joins the royal family, she will also have the opportunity to borrow the jewelry in the queen's vault. In fact, Queen Elizabeth reportedly offered the "Suits" star to pick a tiara for her wedding day as the monarch's engagement gift to Prince Harry's fiancée. Markle's options include the Strathmore Rose tiara, the lotus flower tiara and Queen Mary's fringe tiara.

What tiara do you think will Markle choose for her wedding with Prince Harry? Drop a comment below.