The Princess of Wales appeared to channel her late mother-in-law Princess Diana in a stunning polka dress as she attended one of the royals' most historic services.
Kate dazzled in an Alessandra Rich design as she proudly supported King Charles, Queen Camilla and husband Prince William at a service of the most Noble Order of the Garter at Windsor Castle.
It is the first annual Garter service and procession of Charles' reign and is one of the most colourful events of the royal calendar.
It sees royals and others donning grand velvet robes and plumed hats for a procession from the castle to St George's Chapel for a private service before they return in horse-drawn carriages.
Kate, who is not in the order and therefore not eligible to wear the robes and hat, instead attended the event in the elegant polka dot design dress.
And it looks incredibly similar to a dress worn by Diana at Royal Ascot in 1988 by the designer Victor Edelstein.
Even Kate's new Jennifer Chamandi white heels that come complete with a black toe are almost a mirror image of the ones worn by Diana at Ascot - with this year's event set to kick off tomorrow.
Meanwhile, Kate completed her look today by wearing a pair of pearl earrings that once belonged to Diana.
Before marrying Charles in 1981, Diana was gifted an incredible pair of pearl earrings from jewellers Collingwood as a wedding present.
Now it appears they have been passed on to Kate, who has worn them many times.
As Kate watched the procession, she stood with the Duchess of Edinburgh, who opted for a bright floral dress by Emilia Wickstead with a bright pink headpiece by Jane Taylor Millinery.
At one point they had to hold on to their hats as breezy conditions whipped around Windsor.
They arrived by car ahead of the procession to watch it arrive at St George's Chapel and were seen engaging in chat before Kate was seen beaming as she spotted husband William in the procession.
After the ceremony in the chapel they then joined the other royals in a carriage procession back to Windsor Castle.
The Most Noble Order of the Garter is the oldest British order of chivalry and the world's oldest national order of knighthood still in existence. It was established by King Edward III nearly 700 years ago.
Members of the Order include the King, several senior royals and other Knights or Ladies, who are personally chosen by the monarch for recognition of their work. They include former Prime Ministers Tony Blair and John Major as well as Baroness Amos.
Recipients of the honour are chosen because they have held public office, contributed to national life or served the sovereign personally.
The appointment of Knights and Ladies of the Garter is in the King's gift and is made without consulting ministers.
