To honor the late Queen Elizabeth II’s birthday today—the monarch, who died in 2022, would have turned 100 on April 21—a special reception was held at Buckingham Palace.

Always one to suffuse her fashion choices with meaning, Kate Middleton, the Princess of Wales, chose a special piece of jewelry for the occasion: a three-strand pearl necklace that once belonged to her royal grandmother-in-law.

Though Queen Elizabeth II owned many three-strand pearl necklaces, this particular style—a timeless design—is believed to be the same one seen in Queen Elizabeth II’s final portrait, taken by Ranald Mackechnie. According to Tatler, Middleton has worn this necklace before as well, just days after Queen Elizabeth II’s death.

The necklace was not the only sentimental piece of jewelry that the Princess of Wales wore on Tuesday, either. Middleton also donned a pair of Bahrain pearl drop earrings that previously belonged to Queen Elizabeth; they were a gift from the Hakim of Bahrain on her wedding day in 1947. Elizabeth went on to wear them for numerous royal engagements and appearances over the years.

Middleton wore both family heirlooms with a three quarter-sleeved dress in lavender by Emilia Wickstead (one of her most-worn labels—Catherine Walker perhaps being the other). She accessorized the elegant look further with classic Ralph Lauren pumps.

Also present at the 100th birthday celebration were fellow royals such as King Charles, Queen Camilla, Princess Anne, and Prince Edward. The Prince and Princess of Wales posted a special social media tribute to Queen Elizabeth II today, sharing a selection of images of the late monarch with the caption, “Remembering Her Majesty Queen Elizabeth II on the 100th anniversary of her birth. Inspiring generations through a lifetime of duty.”