Duchess Kate steps out in the queen's choker for Queen Elizabeth and Prince Philip's 70th anniversary dinner

AOL.com editors

Queen Elizabeth and Prince Philip marked a milestone yesterday, celebrating their 70th anniversary together. To mark the milestone, the Palace released new portraits of the royal couple, who last night celebrated at a dinner with family and friends.

We got a glimpse of Prince Harry, Prince William and Duchess Kate as they left for the anniversary dinner held at Windsor Castle. It seemed to be an extravagant affair, as evidenced by Harry and Will's tuxedos, and Kate's gorgeously ornate diamond and pearl choker.

The necklace, which was borrowed from the queen, features four delicate strands of pearls and a diamond pendant. It was also worn by Princess Diana at a state banquet in 1982. Kate recycled a black lace Diane von Furstenberg gown for the occasion, which she has sported before, while pregnant with Charlotte.

Most recently, the pregnant Duchess dazzled in the lace gown at a gala at Kensington Palace to support the Anna Freud Center. She paired the gown with another jewel on loan from the queen, a gorgeous diamond bracelet thatwas gifted to the queen on her wedding day.

Related: The Duchess loves her lace